Once in a while a PC will pick up a wish in my game, be it from a Luckblade or a wild magic effect or whatever, and not realize it; which has led to some rather bizarre events over time.
Character deep in a dungeon somewhere, pining for the comforts of town "I wish I had a feather bed." >poof< Very nice 4-poster feather bed appears, much to everyone's surprise, and far too big to fit out of the door to the room it's in....
All-Human-and-Elf party finds a cave too small for any of them to fit into. One character turns to another: "I wish you were a Hobbit so you could fit in here." >poof< character turns to a Hobbit. But her armour and other gear is still all Human-size....
And I once had a player actually try, this time with a wish she knew she had, the "I wish there was no evil in the world" trick. >poof< As the PC was a Good Cleric he was simply planeshifted to his deity's home plane where there is no evil....