That quote or attitude came from a mentor I had at an internship. He noticed that I was annoyed at people who I thought were stupider than me-- so he told me that:

"If you think you're the smarter one, then the onus is on you to have a smooth business relationship with them. You're the more capable one, so it's within your power to do business with these clients despite their shortcomings."

The great thing about this attitude is that it works even if you aren't smarter than them. If anything, this quote can encourage pretentiousness to turn on itself.