ONLY WHAT YOU SEE, ONLY WHAT YOU ALREADY KNOW?

"The eye sees only what the mind is prepared to comprehend."

Henri Bergson (1859-1941) French philosopher

You can also reverse this (the mind comprehends only what the eye can see), and considering both you should understand the main obstacle to innovation.

When you only see what you already know, and when you only know what you can see, you live in a very limited space.