“Curiosity about life in all of its aspects, I think, is still the secret of great creative people” – Leo Burnett

If you want to be a creative thinker, you must to be curious about EVERYTHING, even all the rules, laws, and ideas that you've been told are true.
Question it all.
Run any idea that doesn't feel "quite right" by what you've experienced and see if it adds up. If it doesn't resonate, if it doesn't make you feel good, then it's not the truth no matter how many people say it is.
A creative thinker approaches life with fresh eyes and an open mind and heart.  For them, life is a laboratory and they are the scientists. They question, experiment, and come to their own unique understanding about everything that intersects their life. They don't accept anything at face value
How do they know when they've found the truth?
That's easy.  When they hear it, it sets them free.