I worked for a mid-size consulting company for six years before starting my own company. I saw a lot of people from my old company try the same thing. None of them made it more than 5 years (I'm nearly at 27).

I think the idea of founding a startup or working for one is a lot different than the reality. A lot of people don't really understand the difference between revenue and profit, or understand that when you have only your own money to fund the company, you're going to risk your entire financial future multiple times in the the early years.

You gotta REALLY want to be independent to push through the tough times unless you are one in a million with a product with an huge profit margin right off the bat. And you gotta learn EVERYthing, or at least enough that you can't be completely fucked over by the lawyer, accountant, etc. you have to hire to grow.

There is a meme I've seen that goes something like, "An entrepreneur is someone who would rather work 100 hours a week for themselves than 40 hours for someone else." I'll add - "often for the same money. "

The big difference of course, like with buying vs. renting, is that I have equity. Many established customers to keep us busy now and multiple independent revenue streams. And since I'm the owner, I won't fire my middle-aged ass and replace me with recent grad.