John lennon syndrome is when a dumbass thinks they’re concerned about peace and social issues and believe they are in touch with nature when in reality they just say the n word, smoke weed, throw a bunch of hindu and buddhist imagery together and call it “inner peace,” and don’t shower. You probably know a lot of these people.

Usually an older person. One who, when younger, engaged in the exact opposite of what he talks about and believes now. Former Libertarian now Liberal and anti-gun (even though once owned half a dozens or so), blames the NRA for gun violence (former NRA member), former Che Guevara shirt wearer in University until he got older and realized he wasn't all that cool, a Marxist who denies he is one, a heavy consumer of all things manufactured when young but who now has become more frugal and now says that consuming has caused Global Warming (now Climate Change and soon to become Global Cooling, again),, etc. I could go on, but why? In short, he's a HYPOCRITE who now bad mouths the very things he used to do when young and who doesn't want the younger generations to live as he did when younger.