So my experience from doing a startup. It depends on the wife/girl. - If they are confident and not risk adverse its OK. My gf practically told me to go get a life and challenge yourself or i'm going to dump you b/c you are clearly doing nothing in your current corporate job. She is still a student though, and there are no family considerations. - other significant others in the team required more convincing, but most saw how 'serious' their loved one was about it and initially opposed it but eventually said ok.

this is really different from a kid/house situation though. i think there is a different level of responsibility if you have others depending on you for financial security. I think then its really a decision between you and your wife that you sit down and discuss. In geneneral though, you want to sell the story and back it up w/ action.