I am 38 yo now and I made 3 career decisions in my life that significantly reduced my income. I never regretted them, quite the contrary. I was never as wealth

I am 38 yo now and I made 3 career decisions in my life that significantly reduced my income. I never regretted them, quite the contrary. I was never as wealthy as you, but proportionally, it is a similar situation. My reserve wouldn't allow me to live for 3 years with no income, but I had the benefit (in my last move) of my wife being able (and willing) to pay the bills on a stable job she likes. My decision process for those radical moves is: will I be able to endure the realistic worst case scenario? In your case, I imagine this scenario would be something like this: failing miserably at your idea, not only financially, but not even enjoying working on it as you predict you will. During this period your family would be living in a significantly lower standard of living. A lot less luxury that 500k/year can afford. After 4 years and having consumed 1/3 or 1/2 of your reserves, you have to go back to the job market. You will find a job that will pay you 250k/year and you will hate less than your current one (this is the realistic part, I really doubt the skills that took you to a 500k job will not get you choices, even after a 4 year gap, if you are willing to earn half that). Do you think you would be ok facing this worst case scenario? If you think it might lead you to desperation, depression and hurt your family relationships, don't do it. If you think it is not the end of the world and all your family is on the same page, do it.