바보=바(라볼수록) 보(고 싶은 사람). gg.. I think if some girls like you, they may say 바보 not stupid but the more they look into your face, the more they want to see you as the meaning of it.

also, some girls like to call me 바보,, so i guess this should be in this discussion heh. They seem to use it A LOT. ( i know it means 'stupid')

Yeah, 맨 땅에 헤딩하기, bumping one's head against the ground. It's equivalent to ‘banging one's head against the wall’ in English.

Another equivalent is '식은 죽 먹기' eating cold porridge in english. It means "That's as easy as pie."