Keys mysteriously change

Every now and then the keys on my keyboard get screwed up.  For example, a P key will input a * and the A key changes to a 0 and it becomes impossible to type.

I've recently figured out that the Num Lock for whatever reason gets turned on.

To disable it, press the FN (Function Key) + the Delete Key / Num LK key.

While it's an easy fix, for some reason I couldn't figure out what was going on.