[mceachen]

I'm one of the founders of http://AdGrok.com -- we're in the current YC batch. I just turned 40 (one week before demo day!), have a wife (we just celebrated our 16th anniversary), and two kids (8 and 10).

I'd look carefully at your situation. Through this whole experience, my wife has been amazingly supportive -- there were no hesitations on her part as to whether I should go for it or not. She's been just as important for me in keeping the AdGrok ball rolling forward as my co-founders have.

Make sure all parties involved know what they're going into. It's my fourth startup (the second I was a founder in), so she knew I was going to be "heads-down" for a decent duration, frequently coming home after she was asleep (or just sleeping at the office). Make sure she's expecting crazy-long work days. You don't want or need her surprised by anything in a month or two.

I've worked with hundreds of hackers through the years, and there's only one common regret voiced by the older of my hacker friends: it's the soul-tearing sadness of not spending enough time with your kids. Just try to keep that in the back of your mind -- you'll have to try to decide what "enough" means.

Good luck!