Now pushing 80, I have led a very active life, which included athletics, hockey, swimming, ski-ing (both down hill and cross-country),mountaineering (reduced to fell-walking in my 40's), tennis and badminton. All of these have gradually become beyond my reach, physically, although I'm still an active walker and on a good day can still manage 8 miles or so. Yes, the gradual deterioration and imposition of limitations is frustrating, but it's also a natural progression, and has led me into other less physically demanding but still enjoyable activities. Walking our 2 dogs, writing (poetry), guitar, attending theatre and musical performances, reading (lots!), travel (more UK-based these days but still so much to see here)... it doesn't really matter, as long as you fill the gap. I'll only feel cheated as regards "doing things for the last time" is concerned when "breathing" is added to the list, but hopefully not for a while yet.