1. When you are in a serious amount
trouble.
e.g. "
Im in deep shit."
2. A seriously dark or over thought idea.
e.g. Person
1: "Life is completely pointless"
Person 2: "Wow, thats some deep shit."
3. When you are in the middle of a shit and you start going into deep thought and all ignore around you, eventually realise you spend way too long on the toilet then you should have.