The next job can absolutely be used as training for your next gig. Also, the next job can be your financial foundation as you start your next gig on the side. Running a startup should not put your family's livelihood at risk. My father is an entrepreneur and frequently had several small side projects going on at any given time while I was growing up. Right now, he's focused on building up one business, but another business he built up previously is still bringing in solid income. Several great companies started as side projects while the founders were occupied with some other "real" job: GitHub, Google (perhaps debatable, but it started while the founders were full-time students), Facebook, Basecamp, and the list goes on and on. I once read James Altucher explain that he stayed at his "real" job for two years while he built up his side business. By the time he quit to work on his startup full-time, the startup was already extremely healthy with several full-time employees and enough customers to profitably pay everyone a great salary. Of course, you'll have to talk to your new employer to work out the legality of creating side projects. But if you pursue building something up on the side, you'll be joining a long tradition of entrepreneurs who have done the same, some of whom have built companies that will be remembered for centuries.