For myself, absolutely not. I've never regretted quitting a job, or making almost any life change. Not that things have always gone well, but looking back and s

For myself, absolutely not. I've never regretted quitting a job, or making almost any life change. Not that things have always gone well, but looking back and second-guessing yourself is just totally a recipe for misery and the worst kind of depressive introspection. I suspect that if you need to ask this question on HN, then you are not ready to quit. However, you have a valuable side-business, have you thought about trying to staff trusted people in or have your partner run it, with you as part-time consultant? If your relationship with people at your day job is as solid as you imply, you might want to take an unpaid leave of absence, and spend 6 months trying to drive your side-business to the point where you don't have any further doubts. Don't underestimate the importance of a near-passive income that you control. For most of us, starting your own business is the only viable way to attain this, and ensure continued income when you decide to retire.