Talking to another Master's racer yesterday about how we forget stuff because our brains are full.
Case in point: I'm Ebay'ing a bunch of parts I've accumulated. I'm going through boxes and finding stuff I didn't realize I had. Writing up a listing for a new 120 stem I found in a box (I've moved 5 times in 5 years so things are a little disorganized). Don't remember where I bought it but then it hits me that I was getting ready to look for that exact stem for one of my bikes.
I figure the next step in the aging process is when you put that stem up on Ebay, realize you need one, then bid on your own stem.