When you tape you peehole shut and jerk off so the cum builds pressure in your dick and it all explodes out like a waterfall.

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.

The act of taking the filter out of a cigarette butt, heating it up, sliding up the plastic sleeve of a pack of cigarettes, sticking it through the plastic and light the other end of the paper on fire. The rule of gravity doesn't apply and the smoke from the paper burning will fall down like a waterfall.