Person who lies constantly and tries to make themselves seem cool, also a person who acts different when you are hanging out with him only, then when you are hanging with him in a group.

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.

Someone who does not believe the still as of yet unproven arrogant theistic claim that "God exists" despite the total lack of empirical evidence for any God(s) what so ever, and despite having thousands of years head start to find any.

A large interbred specimen, usually humanoid that feasts on sympathy. They will go out of their way to make others miserable and attach themselves to a leader for protection.