I made all kinds of dumba$$ mistakes in the early years of gun owning.
Forgot the range key/ tag.
Brought the wrong ammo for the gun/s I brought.
Forgot trigger lock/ case keys.
Brought the correct gun and ammo combo, but the wrong magazines.
Brought a case of clays, two boxes of 12g, and the manual clay thrower and left the damn shotgun in the safe.
I'm sure there's plenty I've forgot.
I lost track of the # of times at the beginning where I'd show up at the range and the guns would be in the bag, but no magazines, or something dumb like that.