I know what you mean. I'm 63 and am constantly amazed that I'm still on the planet.I have finally admitted that I need a new steel knee and I will be starting the process in October.I was trying to hold out until I was 65 but it needs doing now.I'll be 64 before it happens anyway.
My fear is if it doesn't work, and 10% of them don't, it will curtail or even end my riding.Which is still one of my greatest pleasures.