I always wanted to make a DND character that’s a warrior but was raised with mages so he believed he was a mage. The mages were just too nice to tell him that he was a warrior and kept on encouraging him on his “spells”. He would throw a Molotov cocktail and call it fireball and other antics. Sometimes he would get frustrated and punch things and call it mage fist.
Once played a barbarian who told everyone they were a wizard. They practiced time magic, and using their magic staff (great hammer), they took the very years of life away from their victims.
Had a bard companion who would advise people against telling him he’s not casting spells, he’s just hitting people very hard, as that enrages him and he goes into a “casting rage”
There was a D20Deathmatch where one of the characters was a barbarian who tried to extort a wizzard to make him a wizzard and got cursed into the behaviour you described.
