|1.||I don't give three fucks|
When the person in question, does not have the capacity to actually care about what you are saying, but does have bit of intrest. So the amount of fucks given cannot be great.
So they might give two.
Person 1: Do you wanna know about this REALLY funny thing?!
Person 2: I DON'T GIVE THREE FUCKS
Person 1: No, you give two :-)