When I was in High School, I took up tennis. My friend and I spent at least two hours every day except Sunday playing the game. Within just a few months, we were the team to beat on any court we played on. We would challenge anyone, and usually won. High schoolers, college players--it didn't matter. I played tennis even when I had no one to play with. I would spend hours serving, beating the ball against the wall, or whatever I could do to try to improve my game.
Today, I went to play tennis with my two younger daughters and their friend. I had a good time. In my brain, I knew every move I needed to make, every shot that would win the point. Unfortunately, my tennis playing days were 30 years ago. I still did okay, but was frustrated at all of the shots that I missed. Balls I was just too slow to get to, shots that I turned my wrist just a little too far, or a little too short. I realize that if I played every day, like I did when I was 17, I could probably get some of that back, but I know deep down that it will never be the same as I remember. Maybe it never was. That's the advantage of memory. I still love the game though.
Stay young. Live in the present, not in your memory. Stick.