I love mystery. It stimulates the mind. It keeps us busy, makes us useful and therefore meaningful.
I'm reminded of the fact that most numbers are irrational. Most of human experience is irrational, and only a small amount may ever make sense to us.
I've made music since I was 5, and now I'm 44. What keeps it interesting? What keeps it interesting is that one can always improve; the only limit is the ability to be honest about shortcomings. You must be able to honestly assess your abilities.
A good friend is a great singer, but he didn't really think so. To paraphrase, "I'm not a good singer. I just always sing within my limits." That's a good singer and a good musician. It is honest recognition. It is 'Above all to thine own self be true,' to a beat. I'll see if he minds that I tell everyone his name.
Each time I pick up a guitar, sit down at a piano or even just recall music in my head, it's another opportunity to get better provided that any half-baked certainties slow me down or block my path altogether.