Petapixel provided a link to this (now outdated) blog of sayings from a Professor of Photography. I don't usually pay much attention to such people, preferring to hear from favourite artists themselves, but some of this guy's comments are priceless. Worth a few minutes to explore the Prof's take on the medium and its would-be practitioners.
http://shitmyphotoprofsays.tumblr.com
One of my personal favourites (on the "art" side) is:"Don’t default to your intelligence. Your intelligence will let you down. It makes you overthink things. But feel- you can never overfeel things."
— Roma