One of the biggest changes for myself in regards to my training as compared to when I was younger.
When I was younger the workouts were something I had to do to get the muscles that I wanted. Today the workouts are the reason I lift. Having the muscles is just a fringe benefit more or less.
Don't get me wrong, I want the size, but I don't see the workouts as an obstacle to get through. They are part of the prize as well.
Executing the bar movements is as much a joy for me as seeing the results.