Three old ornery grandmas were sitting on a bench outside a nursing home. About then an old man walked by, and one of the old grandmas says, "We bet we can tell how old you are." * *The old man said, "There ain't no way you can guess it." * *One of the ornery grandmas said, "Sure we can! Just drop your undershorts and we can tell your exact age." * *He did. * *The grandmas stared at him for a while and then they all piped up and said,* "You're 84 years old!" * *The old man was stunned.* "Amazing! How did you guess that?" * *The ornery old grandmas, laughed.* Slapping their knees and grinning from ear to ear, all three happily yelled in unison, "You told us yesterday!"