I'm kind of terrified of "At the end of the day, your life happiness will not be dominated by your career." Hopefully he means that primarily for employees, not for startup founders, and even then, I know a lot of people who work in research, engineering, etc. where career is by far #1.
Even Steve Jobs said that having kids was more fulfilling than starting companies and creating products. If you're a startup founder, there's a few ways you can go. You can spend a few years working very hard in the hopes that you get rich. Then you have financial independence, which solves a lot of problems and allows you to focus on doing fulfilling but less lucrative things with your life. If you're not going for a huge liquidity event, you can spend a few years working very hard in the hopes that you can create a successful and sustainable business which, hopefully, you can happily spend a good long time working at in a role you created to suit your own skills and interests, like "CEO".
There are always exceptions, and there's a romantic appeal to figures like Erdos, but it's a huge disservice and a huge sense of entitlement to expect a career, of all things, to take a central place in a happy and balanced life.