This is not correct, you don't 'pretty much always end up getting paid for hard work'.

I've worked in a few startups, as well as had my own where I was working 6-7 days a week 15+hours on most week days, and it didn't result in a big pay day. I've had lots of stock in bankrupt companies and experience to show for it.

However, I will say that it is possible you'll gain lots of experience, and I wouldn't give up my long hours in my youth for anything else. It was great experience and I loved being in the thick of it.

As I've gotten older, I've started to appreciate more of a balance.