The ultimate life hack is the ability to quickly reset and recover. From a bad interaction. From a bad day. From a missed workout. From a poor decision. You can start over whenever you want. You can't always control what happened, but you can control how long you carry it.
The most underrated act of kindness is simply letting people be. Let them mispronounce a word, talk too much about a show they love, or get excited about something you don't quite understand. Everyone has something that lights them up, let them shine, even if it's not your thing.