I worked nights as a motorcycle courier for a couple of years in all seasons and saw what I call the "battlefield" of riding; crashes, machine failure, exhaustion, self-employed poverty and the most irresponsible riding you could imagine. On the other hand, the was a connection between rider and machine like I'd never experienced before, real riding talent, the magic of the night-time economy and a real community between riders.
However, I'm with Crossbolt on this one - there's a feeling when your number is coming up, and I very much had that feeling towards the end of my time doing that work.
You're smart to acknowledge that our luck doesn't run forever. That doesn't mean that it is a black and white choice, however; ride or not ride. When my other half and I managed to dig ourselves out of the small pit we found ourselves in and moved away, I scaled back my riding to commuting to work in the daylight, and for the first time in a decade I'm going to give myself the winter off riding and put the bike away.
So I guess, in summary, what I'm saying is that you shouldn't ignore any doubt that you've had; but you can scale back rather than stop; it's not all or nothing.
And that's my thought of the day.