Why are these four words the most dangerous in the English language?
Because when you utter these words, you have closed your mind to the possibilities.
Let's say someone is about to give a presentation. You hear its title and you groan, "I already know that."
What happens next?
You turn off your mind. You start doodling or making a list of things to do. Or you start reading ahead to see what the next speaker on the agenda should have to say.
You've just closed off any possibility that you might actually learn something new.
Maybe you DO think you know this topic. But are you experiencing success? Any success at all?
If you ARE successful, wouldn't you like MORE?
Then uncross your arms and get that look off your face. You know the one I'm talking about. The one that says, "I already know that."