Taking your post to lean to the audio hobby:
Not far behind you, for sure things change. As we age, the fluid in our inner ear thickens reducing our high frequencies. Getting old stinks, but I don't like the alternative.
Going through life most people have some hearing loss from loud sounds. Gunfire ( defective Military ear plugs), Who concerts, Lawn mowers etc. We have been pretty careful, but where I had been tested to 22K in my 20's, the last tweeters I tested on the bench seemed to roll off above 15K. Not bad for an old fart though. My father loved his AR-2's, but he flew both seats in B-25's so had no HF hearing at all. Everyone ends up in a different place.
How important music is and can you continue to get evolved for listening I do not think is directly age related. Not for me at least. I want music almost all the time and I still just sit and listen.
How to keep your mind sharp is a topic that fortunately has been studied a little. Good old crossword puzzles, constant reading, thinking and discussing not just watching the news. Basically, to keep your brain, use it. The topic of age and retirement comes up occasionally. I have known people in their 90's who were sharper than I ever was, and people in their 50's that should be put to pasture. It depends. ( I have also known people in their 30's that were dumber than a stick in the mud, so age may not treat them well) .
How we deal with stress effects our thinking. I loved the quote from Junior Johnson ( NASCAR driver, chief, owner) " I don't get stressed, I cause it". I suggest, just my personal view, stress has a lot more to do with health than just food. I have been on a "seafood diet" all my life. I see food. I eat it. We are learning it all has far more to do with genetics. I am so far very lucky to not be on any medications. I should take Glucosamine for my joints, but I forget. ( it does work)