[MrRubix]

Oh man to reply to this topic would require more text than I care to write.

I'll just say "Yeah, language is full of these. It arises from the inherently subjective nature of spectrums in a given meaning." Obviously "need" is an extremely strong form of "want." It isn't NECESSARY that you have an umbrella when you go out into the rain. It isn't NECESSARY that you need to eat food (you COULD die) -- but you want to survive, and so you really, really want food -- you "need" food. It's NECESSARY that we need food in order TO survive, but we say we "need food" because "we really want to survive."

Much of the "cutoffs" we derive for these terms are evolutionary, as is practically everything else in life.

But cases like this arise everywhere. Metonyms, synecdoches, etc -- also very common in our language.