The human wants to put me in a bag and drive me to some person who will poke and prod me so I hide behind the couch.
What is flight?
The other cat I live with is sitting in my favorite spot so I hiss at him.
What is fight?
The human is moving some large noisy object across the carpet so I hide under the bed until the nightmare is over.
What is flight? Have you ever run away from a situation? What was going on that you didn't want to deal with?