Okay, so I've come to the conclusion that we have too many greetings.
A few days ago, I meant to give my friend a high five, and he was expecting a handshake and accused me of giving sucky ass hand shakes. Afterwards, the same guy held his hand out wide, so I went to shake it, and he said "no, hug". After that, I held out my fist in a pound it gesture to my friend, and he flinched.