To be "shook to the core," you simply can not fathom something resulting you to be in a state in which you can not easily speak other words than "shook to the core." This is a verb used to properly demonstrate your feelings towards something or someone's actions or state of being.
Gabriel: "Did you see what he just did?"
Human: "Yeah, I am surprised!"
Gabriel: "I am Shook to the core! I can't believe it!"
Human: *nods in confirmation*
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!