Moonlighting to Full-time venture. How successful have you been?

This is probably something a lot of first-time entrepreneurs face. You have an idea. You start working on it, toiling away nights and weekends. But you realize you need to devote far more time and effort to really elevate your startup to a greater level. Execution is the key that unlocks the door. To execute you need to promote, listen to your customers, spend countless waking hours thinking and working on it, invest, pitch, hire, and much more.

Working a full-time gig gives you only so much time and mental bandwidth to do this - your odds of failing I suppose go up exponentially. Probably the worst and saddest outcome being your startup and energy just fizzling away.

I'm curious to know the experiences of some of who have started off moonlighting and successfully transitioned. If you haven't yet, what are your thoughts? What were your experiences? Did some of you quit your jobs to pursue the dream from day one?

If there has been an earlier discussion about this, I'd appreciate pointers.