Defense mechanisms are things people do to protect themselves from unpleasant emotions. It's a way for people to avoid dealing with things that are hard for them to accept. For example, if someone is feeling nervous about a test, they might make up a story in their head about why it's not really important. This would be using a defense mechanism to avoid accepting and dealing with the feeling of being scared. Another common defense mechanism is pretending something didn't happen or that it wasn't as bad as it really was. So if someone did something wrong, they might pretend it didn't happen or that it isn't really wrong. This can help them avoid feeling guilty or embarrassed.