Grandma told me that when she passed away she wants to be a tree, and so she could live forever.
But I'm not gonna lie, it was a nice toasty fire...
Okay, so basically, Grandma wanted to become a tree after she kicks the bucket so she can live forever, right? But then the joke teller is all like, "Nah, I burned her corpse instead." You probably don't understand it because you are too busy eating glue, dumbo.