A close friend of mine was debating for months/years about starting his own endeavor. And we would have tons of discussions around the positives of it and how to start it, why it makes sense or doesnt make sense. 

I am proud to say he has taken a jump into the unknown and finally said "screw it I want to go forward with it". He just put up a good blog post regarding the thoughts he went through before and is currently going through right now.

Take a look http://www.trevormcleod.com/2011/06/some-difficult-questions/ 

These are questions I believe many startup folks are thinking and asking as well.