I visited a customer this afternoon to do muffin inspection. He said that the system is churning out random strawberry muffins when it's only configured to make blueberry muffins. However, he couldn't pin down the exact sequence which triggered strawberry muffins to appear. I told him I couldn't help him unless the problem is reproducible. But I visited him to check out his system anyway. For 2-3 hours, we watched blueberry muffins come out from the assembly line without a hitch. Finally, my customer said he should stick my pic on the system instead since the system seemed terrified of my presence. I told him to call me next time an errant strawberry muffin turned up.

There you go, a case study in IT trouble-shooting.