Imagine if you accidentally tried your breast size with your intelligence, but the expanded growth started to mess with your hormones so you started to leak out your IQ in the form of breast milk.
"Fuck!! They're so... so, umm... like... super milky an' growing still!!"
The wish you'd made hadn't been the most egregious when it came to 'poorly thought out commands given to an eldritch being of cosmic power', that I'd ever seen...
And on the surface, an entirely reasonable and fair wish...
"...I wish that my IQ was directly linked to how big my breasts are..."
That's all you had said, and all that the entity you'd summoned used as their 'basis' for completing the required contact that now existed before them.
"...Very well mortal, your immense knowledge is now directly tied to your bosom's size, composition, and production. The contract is complete..."
Then, in a flash, the unknowable and formless entity vanished without a trace, leaving you with natural and full E-cup breasts that strained against your B-cup sports bra in a comical fashion...
What happened in the intervening thirty-ish days has been more than you could have every bargained for, and certainly more than you (or at least, the 'you' that you were) would have ever wanted.
See cosmic beings of incomprehensible origins aren't going to be the most 'aware' of human biology, and will take the wish that is put before them as literally as possible.
You wanted larger breasts that was directly linked your intelligence - you got that. Now your extremely full and very productive milky breasts have accelerated to E-cups, but the hormones & biological processes that made it possible are still running...
And if your breast size is to be directly tied to your intelligence as it was at the beginning, then it's a simple matter for a fifth-dimensional being to tie the mental concept of 'IQ' to the biological process of 'milk production'.
Sure it started small, with a little 'softening around the edges' of your mind...
"...Sorry for being late to the management team all-hands, I got lost in something and missed my Calendar notification..."
And add mistake here or there...
"...I don't understand, I've done this process, like, a hundred times before... why am I getting so lost on this..."
To larger and larger 'goofs' on the daily...
"...Like, ohmygawd!!! Boss!! I'm like, so sorry for getting my iced frappe all over you!! Can I, like, help you clean up at least..."
But as your intelligence slowly drained and converted to more milk... denser breast tissue... perkier breasts... and a lowering sense of what 'lewd' and 'inappropriate' meant to you...
No one around you saw things as anything other than 'Just Kat being Kat', and acting/looking as (to them) you had always been.
"...Well there's our favorite Administrative Assistant, here to brighten our day are you Kitty Kat..."
It all felt so natural...
Just as it had always been for you your whole life. After all, you've always had your big milk tanks to get you through life. How else were you going to survive when you've spent your whole life with the IQ of a fake house plant?
"Something wrong girl?" your officemate Clarissa asked, seeing you staring off into the middle-distance (though far for the first time), "You're lookin' a little 'spacier' than usual over there."
"Wha?" coming back to the fore, you lock eyes with Clarissa, not even wiping the drool from your parted lips that had started to fall down to your cavernous cleavage, as you turn to face her, "Yeah! Sorry, I jus' had this... like... weird dream last night tha' I was some kinda bossy person here... it was sooooooo weird, lol."