Placing your hands on the rear end of your torso and thrusting with powerful strokes as to imitate a Gorilla. A full size Gorilla Suit is also highly recommended. To add to the effect, make loud noises as to imitate a Gorilla.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.

having sexual intercorse with a man that is much bigger than the lady.

Like doggy style but you stand over your partner like a gorilla