I microwaved a fork and nothing happened
How did you do that?
I left the fork in the microwave for 1 minute.
Maybe it was a plastic fork? You should never put anything metalic in a microwave.
My reasoning says it should have melted, if it was plastic, it should have melted.
There is no logical reason to microwave a fork.   It doesnt matter what type of fork it was, you are lucky that there was no damage.