lose one's marbles/mind
сойти с ума, "слететь с катушек"
Georgina seems to have lost her marbles because she doesn't behave reasonably.
- able to (do something) standing on one's head
- beat (something) into (someone's) head
- bite (someone's) head off
- bring (something) to a head
- bury/hide one's head in the sand
- butt heads with (someone)
- count heads
- drum (something) into (someone's) head
- get a head start
- get into (someone's) head
- get it into one's head to (do something)
- get (someone or something) out of one's head/mind
- get (something) into/through (someone's) head