Let adversity teach you strategy without teaching you bitterness.

Hard experience makes you better at reading situations, and it also offers you bitterness as a package deal. Strategy is useful and portable; bitterness feels like clear sight and slowly narrows what you can see, because it requires you to expect the worst in order to stay consistent. The trick is taking one without the other, which takes attention rather than willpower. It rarely happens by default.

Notice whether your conclusions about people are getting more precise or just more negative. Precision distinguishes; bitterness generalises. When you catch yourself generalising, look for the counterexample you already know about.