I've lived various stretches of my life in balanced and utterly imbalanced states and I can say with quite a bit of certainty that balance always wins, both in terms of happiness and performance.
The other thing about sacrificing everything for your startup that people seem to forget is that when you sacrifice everything and your startup fails -- which, statistically, it will -- you're left with nothing. Having no money is an inconvenience next to being in poor health and having nothing else in life to fall back on emotionally.
At any point in life where you're sacrificing everything and removing all you have to fall back on, you're setting yourself up for failure. Nothing in life is certain, but nothing in life is less certain than a startup.
The other thing about sacrificing everything for your startup that people seem to forget is that when you sacrifice everything and your startup fails -- which, statistically, it will -- you're left with nothing. Having no money is an inconvenience next to being in poor health and having nothing else in life to fall back on emotionally.
At any point in life where you're sacrificing everything and removing all you have to fall back on, you're setting yourself up for failure. Nothing in life is certain, but nothing in life is less certain than a startup.