I'm tired of it.
For our "big" project in our Software Engineering degree we have to write essentially a virtual machine for a hypothetical computer, which we can then write a multithreaded operating system that we can deploy on the machine.
I've finished the vm for the computer. We then have to do testing by running machine code programs the professor has written on it (among our own as well). It freaks out and goes into an infinite loop. I spent five hours going through my code checking each line, debugging, etc. I finally give up, grab a whiteboard marker, and go at it on my sliding glass door all Charlie Eppes from Numb3rs style. I then can see right there the professor was the issue, not my code. He addresses the wrong memory location several times. Change his machine code to point to the right memory location, and boom! Works like a charm.
I have to stop doubting my abilities. Anyone else doubt themselves to the point sometimes where it has to be you the one wrong, and don't even consider the other parties involved?