I don't have to imagine it, I know how hard it can be for someone that has Alzheimer's. My grandfather had Alzheimer's and it was bad (very very bad). I do believe that Alzheimer's is worse then cancer (I really do). With cancer if found out early it can be treated and such. With Alzheimer's the person slowly dies (he died from Alzheimer's, he didn't want to eat and everything just started shutting down) and slowly forgets everything (not just "somethings" but everything from every person he knew, to knowing how to talk, and eat and such). It's very hard on the person, but for the loved ones around... it's also very hard (seeing someone they love forget them and slowly "fade" away), they got to take care of them, feed them, and so on and so on.
My heart goes out to anyone that has Alzheimer's and to the family of ones who has Alzheimer's. I know first hand that it's not fun at all, something no one should joke about (it's a very very bad disease).