I believe it is subjective to the individual. If a person doesn't have any ties (relatives or friends on the outside) they might never get to that point. What was key for me was that before I went first went down, I was a hobbyist programmer and had an independent, many-years long MMO game project under way. Being in prison chafed at me horrible because every day I felt like nothing was being accomplished towards it! I knew I was loosing time from completing that goal.

Its funny how the goal that I wanted to work towards changed from that game to a successful life.