I hear Iverson's voice in my head whenever I feel like talking about practice. I'm 66 years old and have been playing for over 50 years. I'm a few months away from retiring from my day gig. I still try to practice 3-4 hours a day. 3 feels like a minimum for me to improve slightly. That extra hour makes a big difference to me in terms of learning new material and learning to improve and add to my repertoire…
We all have responsibilities and as we get older, we end up having more commitments instead of less. Sometimes, it feels selfish or self-indulgent to continue to voraciously try to improve but I view it as a long game.
I plan to keep working hard and improving until I can no longer play the instrument.
And closely related is practicing vs. entertaining yourself. When I was at the University of Miami, I was wandering the practice hall in the jazz department and a few guys were sneakily listening in on a trombone player who was awful. Struggling to play his major scales. Stan Samole wandered by and yelled at the kids to get away from the practice room door and said something like, “The guy is in there doing what he is supposed to do. He's working on stuff that he CAN'T play so he can get better. If you're practicing and you sound great, it's because you're entertaining yourself and not practicing!”.
I NEVER FORGOT THAT LESSON!
Barney Kessel told me once in a lesson that there are only 2 reasons to open the guitar case. You are either trying to learn something or you are making money.
I differ from that viewpoint in that I believe it's important to entertain yourself as long as that is not ALL that you do. Entertaining yourself keeps you grounded and gives you a sense of satisfaction that all the hard work and dedication you are putting in has paid off.
It doesn't matter if I am playing for an audience or not. I am competing with myself and am still striving to get better.