Leonardo da Vinci

He who is fixed to a star does not change his mind.

The greatest deception men suffer is from their own opinions.

Learning never exhausts the mind.

It's an ear job, not an eye job.

You don't work on something for six years and be blind to the myriad of other approaches.

It is the eye of ignorance that assigns a fixed and unchangeable color to every object; beware of this stumbling block.