There is a homeless man, you will recognize him. He has the dime sized hole in his left cheek. He will ask for chewing tobacco. If you give him some he'll ask if you have a piece of paper. If you do he will take it, and spit on it greasy black tobacco spit. He'll then neatly fold it in two and hand it back to you and thank you kindly. Later, if you unfold the paper you will be pleasantly surprised by words formed by the spit. They will describe a memory you had lost that was very good.
This was something you needed to know.