Actually, the only time I’m reminded that I’m old(er) is when I look in the mirror and don’t see a 20-year-old. Having a hip replaced a few years ago made me feel older but, now, I’m good as new and can do everything I’ve always done.
I guess what reminds me that I’m not THAT old is exactly that — I don’t feel any meaningful body limitations yet, and I don’t have any health issues. Knock on wood.