ridiculous

to be amazed

to be utterly amazed

to be flabbergasted

look of amazement

astonished beyond words

to be dumbfounded

laughing in astonishment (at something silly or stupid)

dumbfounded

dementia ②stupidity

senile dementia

dementia praecox

dementia

a (single) reading (a perusal) leaves one dumbfounded

senile dementia

paralytic dementia

dementia pugilistica

stupid chatter

fools use people to pick up things lying at their own feet

only a fool with no manners asks for another helping more than once

an idiot will swallow anything

you're a fool if you dance, and a fool if you just look on; we're all fools, so let's dance

dementia praecox

(I'm) shocked