Puts me in mind of the Bruce Springsteen song, "Glory Days," in which the people he meets talk of nothing but the good times they had in their "glory days," but have done nothing since.
Yes, and so what? I don't buy your argument, as it seems to assume that just because you have a happy memory in mid-life, that's somehow not as good as a memory from earlier on in your life. Just because a memory goes back to an earlier time doesn't mean that it is higher quality than a more recent memory. One of the activities that I really enjoy is backpacking, which I've been fortunate to be able to do for close to 60 years. My memory of the first trip I did is still fairly vivid, but the trips I've done more recently, say in the past two years, are just as happy. It matters not to me that these newer memories won't last as long as my earliest memories of the same sort of activity.
Edit: I didn't realize I was restating some of the things that
@Dr. Courtney said, especially about the Springsteen song, and reliving old memories without making new ones along the way.
Although you pay lip service to exercising some caution in your remarks below, it still seems like you are trying to rationalize immediate gratification. I'm immensely grateful that I didn't spend every nickel I earned while I was working, because now I have a comfortable income to be able to indulge the hobbies and activities I enjoy.
See the Aesop fable, "The Ant and the Grasshopper."