[ryancarson]

I think it comes down to personality. For better or worse, I have a personality that allows me to barrel into big-risk situations and not worry. I don't think it's bravery though, it's closer to naive optimism (hence the name of my blog).

If you have no choice but to be a Single-Founder, then it's probably down to whether or not you could survive your startup failing. If you can, then it's down to whether or not you feel happy taking the risk.