Bananas do not grow on trees. Rather, they grow from a root structure that produces an above ground stem. The plant is specifically classified as an arborescent (tree-like) perennial herb; in fact, it is the largest herbaceous flowering plant. The banana plant being an herb is that the banana itself is a berry.
Our studies at University College London have shown that the cerebellum can predict sensations when your own movement causes them but not when someone else does. When you try to tickle yourself, the cerebellum predicts the sensation and this prediction is used to cancel the response of other brain areas to the tickle.