I read this advice that suggested you should mentally wish good will towards everyone you run into, because at some telepathic level they will mentally pick up on it, and respond in a friendly manner back towards you. It’s a way to create a sense of harmony wherever you go.
Even if this idea of mental telepathy wasn’t fully true, I still think that if you get into the habit of wishing good will towards everyone you run into, it’s going to make life a lot more pleasant for yourself. What’s the worse that can happen from being deliberately kind?