We have all been there at some time or other. If not a computer or some musical fix, it may be something on the car or even a kitchen appliance.
I remember one time wondering what had gone wrong on the old desktop, it was throwing up all sorts of odd wobblies. No virus found, a system restore didn't fix it, checked all sorts of other things, only to find that the enter key was jammed down on the keyboard with a crumb. (Serves me right for eating a sandwich over it the night before)