In 1974, after we got married I had a gunsmith work on my pistol. When the MRHYN and I went to collect it he gave me the stock trigger that had been replaced by a custom one. She promptly put it in her purse. It's still there and I can't recall the last time she switched purse without the trigger being switched as well.
I guess that counts as a superstition.
As for me, I carry an expended 7.62 round that ricocheted off a wall in Mogadishu, Somalia and fell at my feet; it was too hot to touch the first time I picked it up. Depending on my state of sobriety when I tell the story the bullet hit;
a) Two inches from my head, or
b) In the space I had just moved from, or (if really plastered)
c) Ricocheted off my helmet.
In truth, it hit about 3-5 feet above my head.
I also carry a P38 can opener on my keychain. It belonged to my father during WWII. I didn't realize how attached I was to it until a TSA goon tried to confiscate it when I went through security. I refused and miss that flight while I scared up an envelope to mail it to me.
Finally, after reading the crash survivability report of my son's new pickup truck combined with his (lack of) driving skills, I've come to the conclusion that wearing a seatbelt in the truck is more of a good luck talisman to safety than any expectation of real restraint and safety.
“The American Republic will endure until the day Congress discovers that it can bribe the public with the public’s money.” Alexis De Tocqueville 1835