Ununderstandability

un'un′der·stand′a·bil′i·ty
- The ability to ununderstand things.

A: Man, how could you forget these simple rules in just a second, you got a problem or anything?
B: I didn't forget them, I just used my ununderstandability.
A: Your what? I... I don't care, I just can't stand your tomfoolery anymore...
B: If you can't 'stand' it, than 'set' on your chair man.
A: You know what? I'm done, deal with your problems alone, I couldn't care less!