I can think of all sorts of thing s I could have done better when I was 42 but if I was 42 now, I don't know what I would do. Probably work when I had to and play when I could, just like before! The thing is, our lives are influenced by the times. I don't have time for any real long term plans now and didn't waste time on them then. I honestly don't see the point in busting your ass when you are young, in hopes that you can enjoy the fruit of your labors when you are old.
The bottom line? At 72 I can't tell you a damned thing! GD