Gold, mined here.
The general root of superstition is that men observe when things hit, and not when they miss; and commit to memory the one, and forget and pass over the other.
Francis Bacon (1561-1626)
These days, some call this phenomenon “confirmation bias”. Others, like pop-psychic charlatans, faith healers and new-age full-moon crystal-chargers, call it “gravy.” Well, if they’re being honest with themselves, anyway, as I’m sure they are – but only when a long way away from other people, only in the privacy of their own minds and only very briefly.