Tree Kid

Listen here, you think it's funny to ask how to get a 'retard kid' out of a tree? First off, that's not cool, calling people names like that. Second, you know that waving is a normal action, right? The punchline implies that the kid is so easily distracted they’d just come down if you waved. It's dumb. But, hey, you wrote the joke, not me, I guess you might be as dumb as the kid.