Oh, I know all about it. Of course, we do very similar things, don’t we? (not necessarily you and I, but our culture). I have heard of stories of people buying used chewing gum, dinner napkins and so on of celebrities. Meanwhile, the Smithsonian has Archie Bunker’s chair and all manner of oddball cultural relics.
So, in a way, it’s not surprising. The major difference is these often involve body parts. I think people thought that these “saints” were so special that by hanging on to a relic, some of it would rub off on them... some magical thinking there.
You seriously have Catholic Derangement Syndrome.