The important thing is not to stop questioning. Curiosity has its own reason for existing.
One who asks a question is a fool for five minutes; one who does not ask a question remains a fool forever.
In all affairs, it's a healthy thing now and then to hang a question mark on the things you have long taken for granted.
Quality questions create a quality life. Successful people ask better questions, and as a result, they get better answers.
The ability to ask the right question is more than half the battle of finding the answer.
The greatest compliment that was ever paid me was when someone asked me what I thought and attended to my answer.