Funny ways to tell someone they're stupid?

[Phantomlight]

This. This one is probably my favorite so far uwu

[Lahin]

I don't have any fancy way of telling someone they're stupid, but seeing your post, I remembered a quote:

“Never argue with an idiot. They will drag you down to their level and beat you with experience.”

― Mark Twain

So, now I'll probably go with "No. I'm not going to argue with you." They won't know I called them stupid. So they won't get angry at me. It's a win-win. XD

[DokiDokiTsuna]

Well, there's 'Not the sharpest tool in the shed/crayon in the box/knife in the drawer', and other such variants.

Personally, I like to use retorts in the vein of their stupidity being contagious. Like "I just lost 10 IQ points reading this", or "I'm losing brain cells here!" I used to use the latter a lot IRL...^^;

[Black_Conscious]

Be dramatic on calling someone dumb

[SpavVy]

My favorite one I found on the internet a while ago would have to be "the wheel's spinning but the hamster is dead."

[KillianRain]

"Awww, cute. Want a cookie?"

[WoollyPAR]

One day you will find your still-living body being dissected by lifeforms of higher intelligence than yourself, such as monkies. Though it's pointless to warn you as your brain is so unevolved you won't even recognize yourself as being in a perilous situation worthy of panic. Just do be careful not to lay down, it'd be a shame if you drowned in your own spit before the monkies ever learn anything from you.

[irene_addler]

your brain cell must be lonely

[cookieroach]

Don't know if it works in english, but one I find funny is "brushing your teeth with the big brush".

[DualDragons]

"I'd compare your intellect to that of a donkey, but that would be insulting to the animal."

[Maps]

“The lights are on but nobody is home.”

[milejdyvan]

SMALL BRAIN!!!! SMOOTH BRAIN!!!!

(I had to add something cuz it wouldn't post lol)

[migxmeg]

I think Blackadder had the greatest insults.

‘Baldrick, your head is as empty as a eunuch’s underpants.’

‘If you put on a floppy hat and a funny codpiece, you might just get by as a fool, but since you wouldn’t know a joke if it got up and gave you a haircut, I doubt it.’

‘The eyes are open, the mouth moves, but Mr Brain has long since departed, hasn’t he, Perce?’

Baldrick, you wouldn’t recognise a subtle plan if it painted itself purple and danced naked on a harpsicord singing “subtle plans are here again”.’

‘Your brain for example- is so minute, Baldrick, that if a hungry cannibal cracked your head open, there wouldn’t be enough to cover a small water biscuit.’

[AnonymousHouseCat]

I once had a friend whose family would say “you’re so pretty...” but it wasn’t a compliment. I have another friend who says “he/she/they’re not the brightest bulb”

[DiegoPalacios]

"you are the product of millions of years of evolution......please behave accordingly"

[gmaximin]

Nincompoop!

(and enjoy the confused stare...)

[WinterFall]

"...I think you forgot to pay your brain bill."

[Ordinaryaverageguy]

"The lights are on but nobody's home" seems to be in the same vein.

[Ordinaryaverageguy]

Blackadder had it down to a science.

From my own family:
"They don't have sense enough to pour piss out of a boot with the directions on the heel."

[AnonymousHouseCat]

Oh! I just remembered these two from my family:
1) This one is for when someone smart does something dumb/you overthink something until it becomes dumb: “so smart they eat their own mocos (snot)” and
2) when a rich person does something dumb: “all dollars and no cents (sense)”