"The Art of Thinking Clearly", written by Rolf Dobelli, is a really interesting book. It gives some how-tos on critical thinking.
One of the traps that we easily fall into is "confirmation bias". It means that when we have an opinion in mind, we usually seek for evidence or proof to confirm it, rather than disconfirm it. We can even ask questions in a way that guide others to give us answers that we want to hear.
It's a natural tendency. We, of course, hope what we say or do is right. It's discomforting to learn that we are wrong, even though that can be true.
How to break it?
Find ways to get disconfirming evidence, know that we need to go through trials and errors to get the truth.