Pika, that was pleasant to read. Bittersweet is a good word for it. I'm 63 years old and headed for retirement. I have section-hiked just over 300 miles of the Appalachian Trail, but I haven't hiked for quite a while. I just don't feel like it anymore because I have fatigue and health issues. I really want to get back to it after I retire. My backpacking buddy moved across the country years ago, but I kept hiking solo for a long time. Now when I view the lovely pictures of my hikes, instead of enjoying them, I feel a crushing sadness. And music isn't very enjoyable for the same reason. I don't think I have regrets, but I just don't like getting old.
Life is a learning curve, and getting old isn't for sissies!