When you're waiting for a very important call, such as a job call-back or a call-back from your crush and you spend most of your day focusing all off your energy and thoughts to try and telekinetically make your phone ring.
Person 1: *hangs up the phone* You bitch
Person 2: What's the matter?
Person 1: I've been building up my call karma all day waiting for my job call-back and that telemarketer just wasted it all trying to sell me something stupid.
Person 2: I hate that.