Categorize the following sentence into one of the five different emotions: anger, confusion, joy, sadness and neutral.

Example input: I KILL YOU SCUM.
Example output: anger
Example explanation: The sentence expresses the emotion - anger by mentioning about killing someone. So, the output is anger.
Q: That guy is gonna regret losing you the rest of his life. You know why i know this? Because i am him 30 years ago.
A:
sadness