Your success will eventually require you to deal with someone difficult, or to stay calm in a situation where someone else is creating tension.
When that time comes, the quote above is a powerful touchstone for finding a way to approach the challenge with generosity. Because no matter how caustic the personality, it is unlikely that the problem person wants to make your life harder. They are busy dealing with their own issues, and quite honestly, perhaps you are also working their last nerve.
If you experience a tense moment today – take a breath and accept that the other party is most likely experiencing a challenge somewhere in their life. Find a way to reach through the tension and offer some kindness. Practice this regularly with strangers, and maybe it will eventually be key in managing an important business relationship.