Larry, that's a diseases known as CRS "Can't Remember S**t", mostly prevalent in older males.
For me, I'll have an immediate need for a part I held onto for years, and after an hour or two looking for it I remember tossing it out, so I buy the part. Usually within a week I'll find the one I didn't toss out after all.I think after I break down and rebuild a different one and buy a new one for the other machine LOL