The family in My Big Fat Greek Wedding bring their grandmother to the U.S. from Greece, because they “weren’t weird enough”. Yiayia has trouble adjusting and shows signs of dementia, thinking she’s been brought to a Turkish prison:

Yiayia: [spoken in Greek] Listen up, ugly Turk. You’re not kidnapping me!
[Gus laughs and tries to hug her, but Yiayia suddenly hits him and runs out the door. Maria and Gus chase after her.]
Gus: Mama, please! The Greeks and the Turks friends now!
Toula: [narrating] We told my grandma the war was over, but she still slept with a knife under her pillow.

Yiayia also frequently wanders, and is shown being returned by an annoyed neighbor who warns them “Keep your mother off my lawn, out of my basement, and away from my roof!” Later, Yiayia is seen making a break for it again, but is repelled by strategically placed sprinklers.

It is unclear whether Yiayia realizes there’s a wedding going on or whether she simply finds a box of keepsakes that jolt her memory at a pivotal time, but she helps main character Toula understand the true depths of her family’s investment in the big event.

Though Yiayia’s function in the script is to provide comic and emotional relief, there’s a darkness to her wacky antics. She also serves as an unspoken reminder that many survivors of atrocities who develop dementia suffer from flashbacks and must relive the horrors of war.