Yes, Jack, that's my experience, too...

I think there's another consideration, though, which is the 'autopilot'. Once you've practised a tune so well that you cannot get it wrong, you have the surreal experience of being able to sit back and watch as if someone else is playing.

When you're first learning a tune, you're having to do all the thinking. The difference between a good player and an average player is the amount of 'processing time' needed when playing. The average player needs more concentrated effort to think about what comes next, because the fingers haven't been trained to do the thinking for you - a good player doesn't have this restriction.

As an accordion player (amongst other instruments), I often find myself mesmerised by the antics of my left hand which seems, at times, to have a mind of its own - I'm not consciously telling it what to do (bass runs, etc.). But this is happening whilst I'm playing a fairly complex tune in the right hand, which I'm not giving any thought to...

Sometimes it can be quite disconcerting, even distracting, and I find I have to 'snap out of it' before disaster occurs!!

As I also use the accordion to accompany myself singing, this ability is a necessity.