I like how people just excuse situations like that concerning the elderly as "they're just old and confused." I'm sure quite a few elderly are very aware of what's going on around them, and are just being immature or rude. My maternal grandmother did that a lot with my sister and I back when we were around the ages of 10-13. My mother scolded her one day when she witnessed this, and we didn't see her for awhile. Next time we saw her she stopped acting rude like that.
I remember once, she said she'd be overjoyed if one of our precious cats died (I quipped back with "you'll die before the oldest one does", a sentence that wasn't true).
My mother also heard this gem over the phone. Grandma thought she hung up after trying to call us, but my mother answered at the last second, and could hear the conversation going on between her grandpa, who was still alive at the time:
Mom: "Hello?"
Grandmother: "The church is over there Tony. TONY."
Grandfather: "What?"
GM:"You just missed the [insert present tense of f-bomb here] church!"
Mom: *chuckle after a bit of shock, calling out to dad* "Did your mother just say the f-word? HELLO? MOM? She can't hear me."
GM: "You know you have to go to the party at Richard's [my uncle] on Friday."
GF: "Yes, I know."
GM: "I hope that little [insert 7-letter b-word here] Alissa [my sister] doesn't go with Jerry [my dad] and Ro [my mom] to the party. She's liable to come.
Needless to say my mother didn't like hearing that last sentence. Grandma was not welcome in our house for the next two months until she apologized for making such a statement. Her reason for calling her that:
"She never says hello to us, or thanks us when we giver her gifts. Amanda [our (adopted) cousin] always does those things."
Mom argued back that she doesn't do that with anyone, nor do my brother and I (we were very quiet until a certain age).
So yeah, not all elderly people are "old and confused".