My Grandpa has what's called Dementia.  Dementia is a condition that gradually affects all functions of the brain starting with memory.  Here's a link to PubMed Health explaining it with better detail.  My Grandpa's memory has been getting worse.  He doesn't remember my name anymore, along with the names of my cousins and the spouses of his children.  Every once in a while he even forgets who his kids are.  He doesn't even remember that he has Dementia but sometimes I think that's a good thing. 

My Grandpa's personality is kind of like the old man in the Tyler Perry movies, if that makes sense. He's always mubling curse words under his breath and joking and teasing everyone. And I think that's what makes things he says or does somewhat humorous.  One question that he always asks about every hour or so is "How old are you anyways?" Sometimes we just say random ages to see his reaction.  Every time we leave his house he says the same thing: "I know your a damn speed demon so be careful out on 210. Last weekend the policeman gave out over two hundred tickets!" One time, my mom made him brownies and one of my brother's friends took one and ate it and my grandpa threatened to "tie him up, throw him in a trash bag and put it out in the river." Ofcourse he was joking, we think. Haha. Whenever he sees my youngest cousin who is four, he'll poke her and say "You little devil!" And she just giggles.

Of all the things he forgets, the one person he remembers is my grandma. One day back when my grandma was still recovering from her stroke, we were talking and he asked, "So, do you know my wife?" I told him I did. He responded with, "Yeah, she's out at the hospital still. Did you know she's eighty-one? We're both getting old. But I tell you, I went and saw her yesterday and she looked just as beautiful as the first day I met her." And they say kids say the darndest things.