Thanks to your own brain, words have the capacity to become your worst enemy. 

JG: it could just be a random word, something attached to something you know, or something that you happened to be thinking at the time you were feeling awful so it became the word that means something bad.
HZ: No words are safe.
JG: No! Because that part of our mind just mashes things together in different ways, and if it mashes two things together at a time when you’re feeling a certain way, that connection sticks, which is where the therapy comes in - unsticking those things.