Is Dementia Contagious?

The doctors say dementia is not contagious, but I am beginning to wonder. In my haste to book an exciting trip to New York, I checked my calendar to make sure I don't have anything going on, scanned my (inconsistent) brain, and decided to buy tickets with Lauren to go to New York - April 3-6. One problem: Grandma's birthday is in there. That doesn't move every year. I have celebrated it with her every year. I am pretty sure that dementia is contagious, because I completely forgot until the next day. I was so apologetic to everyone, but considering Grandma has no memory, we decided that I would just make it up to her. We'll still celebrate her birthday on the 6th, but we'll have a bigger deal some other day to celebrate that she's 80!!! Who knew? She's like a little energizer bunny. She just keeps going, and going, and going. And I get to celebrate her birthday AND go to New York because in the long run... she just won't remember. Still, we will - so I'd better make her souvenir a good one.