From Phaedrus, mediator on the Quotations site, here is the source of Petri's quote:
"When you sell your expertise...you have [a?] limited repertoire. On the other hand, when you sell your ignorance, when you sell your desire to learn something, to create & explore & navigate paths to knowledge - when you sell your curiosity - you sell from a bucket that is infinitely deep, that represents an unlimited repertoire. My expertise has always been my ignorance - my admission & my acceptance of not knowing. My work comes from questions, not from answers!" ~Information Anxiety
by Richard Saul Wurman
He has a web-site, typical American stuff, partners, mission statement, 21st century challenges, are you prepared?, sell, sell, You Must Be In on this.
But the quote is good.