I'm not doing a startup, but I have had to defend my separation of work and life rather strongly in my circles.

Here's my take on it: we're all dying. You get a very limited amount of time to spend in the best amusement park ever. Once it's gone your done. So try and have some fun along the way.

When I'm not working I'm thinking about programming. Or I'm climbing a mountain. Camping. Running. Spending time with my wife. Painting. Playing my guitar. Climbing trees. Occasionally I'm out at the bar with friends.

I prefer to be alone most of the time. It's where I get my energy from. Ultimately you just have to discover what works for you.