One thing I find ultimately fascinating is that when you don't interact with somebody for an extended amount of time, all you have left of them are the memories they gave you. It's so easy to recognize if those memories are mostly good or mostly bad. When somebody has left you with memories that you can easily categorize as mostly bad, it's a clear sign you shouldn't talk to them any more even if they gave you good memories as well. The bad will always cancel out the good