I don't know; or in other words:
I do not
give a fuck about what you're asking me.
Mostly used when you
don't want to start a conversation with someone.
Example:
1. Mom: "What do you want to eat
for dinner, son?"
Son: "I don't know, mom."
2. Joe: "How are you doing that?"
Billy: "Dude, I don't know."
**Real Signification**:
1. Mom: "What do you want to eat for dinner, son?"
Son: "Shut up, mom, I'm doing something more interesting than you."
2. Joe: "How are you doing that?"
Billy: "Dude,
I don't give a damn about you.
Get the fuck out."