Wow, makes me want to get old, even less.
Basically, getting old sucks. But, you will probably be a lot smarter...that's at least some consolation. However, I really do wish I knew then what I know now.
As for 'Stud Muffins'...I'd go a tad younger (5 to 10 years) any more and it's just plain creepy IMO.*
(*disclaimer, my personal opinion here)