I think it all depends. I have savings and jumped before I out-earned my day job. I simply didn't have 2h/day and no days off of my day job. I have tried to do this "on the side" for the past 2-3yrs. It never worked for me. This "build in your free-time" works maybe if you don't work 9-12h/day plus commute min 1h each way and don't care if you don't move your body all day. For me it was too much. I am really happy for you that it worked out so well :). I learned one thing, however. If I need or want to go back and get a job or part-time job it will def. close to my home or home office. And a job where I have so little responsibilities that I can just show up and don't care after my workday is done.

Great article. Love your clear and concise style.