Closed-minded people don’t want their ideas challenged. - Ray Dalio

I learned that if you work hard and creatively, you can have just about anything you want, but not everything you want. Maturity is the ability to reject good alternatives in order to pursue even better ones.

The most important thing is that you develop your own principles and ideally write them down, especially if you are working with others.

Close-minded people have trouble holding two thoughts simultaneously in their minds. They allow their own view to crowd out those of others.
Open-minded people can take in the thoughts of others without losing their ability to think well- they can hold two or more conflicting concepts in their mind and go back and forth between them to assess their relative merits. p197