The meaning of this primitive is obvious from the first moment you look at it, though just what it will be a drop of will differ from case to case. The important thing is not to think of it as something insignificant like a “drop in the bucket” but as something so important that it can change the whole picture—like a drop of arsenic in your mother-in-law’s coffee.

James W. Heisig – Remembering the Kanji vol. 1

This last comment almost made me fall of my chair.