As usual, I approach questions like this with great perplexity: "What would you tell your younger self?"
Although I would kind of like to tell that young fella to zig at some junctures instead of zagging, one has to be careful. Assuming that you like yourself and your life now, would you really want to mess with this outcome? Because you don't know how one small course correction could have altered your life, and you may not then have become the person you are in the place that you now are. Do yo really want to mess with that?
Assuming that such a meetup could occur, I am stymied by the logistics. If my two selves could meet, I can well imagine the younger and good looking self to take one look at this older, decrepit self and run screaming in horror over the nearest cliff. And then my older self would never have had a chance to exist, and we would have a paradox in time.
Would my older self simply vaporize as the younger self plummeted to his doom? Depending on the timing, my two daughters would never have existed and neither would the grandkids. That makes me sorrowful now although neither I nor my scions would have been here to miss ourselves. (Curse you KG; you are making my head hurt.)
Although like everyone else, or so I imagine about everyone else, I replay the past with some regularity, but I am afraid that it never changes. Neither do I except in glacial slowness. For I both am and am not the man that I used to be. I am a conundrum.
"It's a wonderful life." Oops, bad allusion.