I'm currently my grandma's caretaker, and she has hella bad dementia. As in, she'll wake me up 15 times to tell me something, because she'll forget she already told me.
Or, before I needed to give her her pills individually, she took 15 vicodins in one day and she kept on telling me the cat looked cute in stockings and she began sh*tting herself hard.core.
It's hard not to get irritated sometimes, but it's really a sad disease...