Robert Greene wrote about this. I can’t find the passage to give a direct quote but it goes like this:
Life is a game. It’s a game for power. When you’re playing a game, say chess, do you have a habit of listening to your opponent and shaping your strategy based on what they say they’re going to do? In Poker, if your opponent says he’s got a full house, do you believe them and fold?
Of course not. They’re not on your side, you’re playing against them, and as such, you cannot trust anything they say. Your strategy is based solely on what they do. It’s based on their actions.
So next time somebody lies to you, do you really have a reason to be hurt or disappointed? The only person you should be disappointed at is yourself. Why? Because you’ve been led down the path they chose for you – you’ve been led by their lie. Words are meaningless, it is action that matters. It doesn’t matter what people say to you or when they lie because it’s not their words that you should listen to, it’s their actions.