I agree. Tolerance for risk is another big aspect of all this. I'm not married. I don't have kids. So my real only concern is myself right now. Others aren't as lucky.
Hah, I think a large number of people would disagree with you that not being married and not having kids is lucky.
In the context of starting your first startup while you're still young and single: yes, you'd be lucky. Life in general: that's actually unfortunate. =)