Go big or go home.

The founders I work with start to eventually hate me because I repeat it so much: a startup is entirely defined by its growth. A startup isn’t defined by being on the internet. A startup isn’t defined by concentrating on technology. The easiest definition of a startup is simply the one given by Paul Graham: startup = growth.

A startup is impressive because it achieves a level of growth that is practically impossible to believe.

Uber’s early expansion illustrates the point. What impressed observers was not just the technology, but the speed at which drivers, customers and revenue multiplied. A successful startup can achieve growth over a short period that is far outside the ordinary.

That’s why entrepreneurs have to be obsessed with growth. Ask yourself, “Is what I’m doing helping my growth?” If yes, keep doing it. If it’s not, stop and find something that will help growth.

That’s not a comfortable situation to be in. Growth hurts. It can’t be planned, it doesn’t follow a roadmap. You’re dreaming if you think that you can control it.

That’s why you shouldn’t evaluate a startup based upon how it looks from the outside. If you really want to see how a startup is doing, go take a look at its founders. If they’re completely stressed, late all the time, and seem to be just barely keeping their heads above water? That’s a good startup. All founders struggle when they’re growing at a pace that breaks all the rules.

Growth can work in two directions.

Strong growth can hide other problems. Investors tend to be more patient while the company keeps advancing. When growth slows and milestones are missed, that patience can vanish. Suddenly every department is examined, leaders are replaced and previously tolerated weaknesses become urgent. Growth never removes the need for a sound company underneath it.

But in startups, you have to accept this situation, because growth is the only way to create real value. That value is the ultimate validation of everything that you’re doing.

No matter what, there will come a day when the growth stops.

If you have a lot of early success, you can think it will go on forever. But growth comes in a series of levels. We like to think about that perfect exponential graph of growth, curving upward to infinity and beyond! But the reality is that there are periods of growth and there are plateaus. Those plateaus are when you’re going to be really evaluated on the inner workings of the company. You have to be prepared for that, and for the scrutiny that comes with slowing growth.

To properly manage growth, you need to keep looking forward and realize that growth is created. It’s not something that just happens. You don’t just put together a perfect product, give it to two people, and then wait for the exponential growth to roll in. After all, people are lazy. Think about how many products you use, but that you never tell anyone about. And think about everything that you love and tell people about, but that no one uses. That’s exactly why you have to go out and chase down growth.

You can have different strategies for chasing down growth at the beginning and then managing it when you’ve reached the tipping point.

I have seen fast-growing companies use very different strategies because their products, industries and goals demanded them. Earlier growth phases at Save, Trusk and Agricool illustrated that variety. A strategy that fits one business does not automatically fit another.

What ambitious companies share is the ability to imagine a larger mission. Agricool spoke about changing how people eat. Damien Morin described Save’s ambition as saving devices, rather than merely replacing broken screens. That scale of purpose can help a team keep moving as growth becomes difficult. Without it, growth can feel frightening without ever becoming an adventure worth pursuing.

The only way to grow fast is to push so much and so hard that it seems to be literally impossible.

No one will tell you this, but every founder has that fear deep inside when they realize that their growing company could very well die. And not in five years or in a year. The company could die tomorrow. Great founders use that fear and that knowledge that it could all disappear to keep pushing and ride the wave.

That’s why you can’t overthink things or try to plan them perfectly. If you say that something is going to take six months, it’ll take longer than that. And maybe it could have happened faster if you had simply said, “This is what we’re going to do,” without putting a timeframe on it. Growing fast can’t happen on a timeline, it can only happen in terms of milestones. Those milestones should be KPI-based, with no calendar for when it will happen.

If you say, “We’re going to get out of beta in 3 months,” how does that help you? It makes much more sense to simply say, “We’re going to get out of beta as soon as we hit 10,000 users.” And then you try to reach 10,000 users as quickly as possible. That’s a mindset and a milestone that can adapt to growth.

Besides you as the entrepreneur, who can be scared of growth? Investors.

Some investors are uncomfortable with spending money before the returns are visible. You need to distinguish useful scrutiny from a reflexive fear of growth. Listen especially to people whose experience helps them understand when rapid growth is worth pursuing.

Understanding your growth and your internal milestones is what lets you know when you’re in a position to ignore those investors who start to worry. Being an entrepreneur is about correctly evaluating what’s going on today and how that is taking your growth forward.

This situation is driven by the fact that the biggest problem in startups is a misalignment between each stakeholder’s level of risk. Your banker’s looking for a risk level of zero, your intern’s risk level is infinite (because they don’t care), your investor’s risk level is a bit higher than your banker’s but not by much, and your risk level as an entrepreneur is based upon your fear of death. And having that fear of death is a good thing, because it pushes you to do things that people would otherwise think impossible, those things that their own risk levels won’t allow them to do.

Growth is hard but short-term growth is more obvious.

There are tons of growth hacking tips out there, they all need to be taken with a grain of salt. Growth hacking is like a chemical reaction — if you’re doing it without having traction and organic growth already, it won’t really help you. You need the combination of elements to really make things heat up.

Manual growth has its limits. When you’ve got all of your friends on board, when your Facebook friends are all in, when you’ve got to reach further and scale outwards, that’s when you move toward growth hacking, automating processes, marketing, that sort of thing. And the only way to know when you’ve gotten to that level is by tracking your metrics.

All of your metric goals should be absolute.

Don’t compare yourself to anyone else. If you have 1.5% conversion, and everyone else in the industry has 0.75% conversion, you shouldn’t think that you’re better than the rest, so things are good. You should be asking yourself how you can raise your 1.5% to 1.6%, and then to 1.7%, and so on.

Absolute metrics are what allow you to push through to the impossible. If you relativize your goals and start comparing yourself to others, you either become depressed (because you aren’t doing as well as they are) or you become complacent (because you’re doing better than them, so it’s all good).

Do the “up or out”.

Your first week, you launch, and you look at your users, your conversation rate, whatever metrics are most important for you. And you try to push those metrics, week over week, just a little bit higher. You know what happens: those small but absolute numbers, growing steadily each week, end up becoming very large numbers.

And don’t forget that your ultimate life metric is revenue: whatever you’re tracking to measure your growth, revenue is the most important one. Forget the idea that you’re concentrating on growing your user base, and you’ll worry about revenue later. It doesn’t make sense. Stop it.

In the end, deciding whether you want to found a startup comes down to a question of whether or not you’re excited by the insanity aspect of growth.

And one way that you can decide if it’s right for you is by giving yourself the Achilles test. When Achilles was a child, his mother saw that he would either live in obscure happiness, or he would die young with glory. When the time came to decide whether or not to go off to the Trojan War, Achilles had to decide between those two fates. He could live at home, have children and grandchildren and then fade into obscurity. But he went the opposite way: he chose glory, died young, but his name has lived on for thousands of years.

Today, we know that there are a lot of ways in this world to be happy and make money that don’t involve trying to find success as a startup. You have a choice between two paths. You have to recognize those paths and make the choice willingly. It’s not necessarily forever — you can choose glory now and then change your mind in five years. But know this: launching a startup is on the path to glory. It’s hard, it’s difficult, it’s dangerous, and it’s not for everyone. You’re the only one who decides if it’s right for you.