two of the greatest, non-sexual, feelings in the world are a) when you have to shit really bad and you finally relieve yourself. And, b) when you clean your ears out with a cotton swab. when you do the two things together, it is the most amazing feeling!
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!