Example:
Sheila: "You used all the gas in my car! How do you expect me to get to work?!"
Jared: "Not my problem."

Example:
"Dude, John found out I slept with Sean and now he thinks I'm a slut!"

"that's not my problem."

Example:
"Not my problem!"

Example:
a: My girlfriend has run away with some shortarse, chav gobshite from Chelmsley Wood! What should I do?

b: Not My Problem....

Example:
That's my problem.

Example:
MArk: I kEeP lOsINg AlL mY bETs

JohnNY: NoT mY pRobLem

Example:
Stranded motorist: Thanks so much for coming out in the rain to give me a jump-start, Buddy! Bless your heart!
Redneck hippie in an ancient Ford F-150: No problemmo, Dude --- it's only what I'd want myself if I was in this same situation. I'm just sorry you walked all that distance to ask me for help... there's a fairly well-off family who lives a good quarter-mile nearer here than I do, and they have several nice vehicles that they could have helped you with.
Motorist: Yeah, well I actually DID ask there, and the smooth-skinned older hombre who came to the door with a TV-remote in his hand just told me curtly, "It's not my problem --- you should have remembered to turn off your headlights."

Redneck: Really?!?? Well, that totally SUX --- I guess HE'S just never had any problems like this, and so he doesn't know that errors like that can happen to anyone!

Example:
Person1: Hey man, I was sick yesterday.
Person2: I missed the part where that's my problem.

Student: I was late because I missed the bus..
Teacher: I missed the part where that's my problem.

Example:
Person: What the hell am I gonna do? My girlfriend left me...mydog ran away...I got fired...
Person2: I missed the part where that's my problem.