My little calculator I've had since high school was once, back then, dropped on the hard wood floor of my parents bedroom. It didn't physically break, but it was kind of knocked out of its little mind for quite a while. I kept it, but I'd test is on simple math first to see if it would give a right or wrong answer. Poor thing was literally telling me things like 2+2=5. I guess it had the electronics version of a concussion.
Some might have ditched it at that point, but I'm glad I kept it because after quite a while...it did get better. Back to its old self and has been fine ever since. Though I'm still kind confused over how a piece of electronic equipment can appear to have "healed" is some sense.