But aren't these already valuable? I now run my own startup and i feel i benefited a lot from my former stints in other startups, even when some of it fell into

But aren't these already valuable? I now run my own startup and i feel i benefited a lot from my former stints in other startups, even when some of it fell into the "what not to do" category :) Also in a startup you're more likely to need to wear multiple hats and deal with uncertainty, which are two things you'd definitely need to deal with even more in your own company.