Think about a topic you know a lot about. An area where you feel very confident in your expertise.
Think about why you feel that way. How do you know you’re an expert? Think about how many hours you’ve spent engrossed in the topic. How many books you’ve read, courses you’ve taken, hours of footage you’ve viewed, other experts you’ve conversed with, etc. Consider all the times you’ve had the opportunity to have your expertise tested and proved up to the challenge. Relive the lessons you’ve passed to others on that topic, and the number of times you’ve been asked directly to opine on it. In short, take a full and honest inventory of the proof of your knowledge.
Now, the next time you’re about to give an opinion on any other topic, ask yourself if you’ve committed the same level of investment into your expertise on this subject.
If the answer is no, replace your opinion with a question, and prepare your mind to hear the honest answer.
This advice, if followed, will make you a much better and happier person.
The Opportunity Machine 