For me it means always ask questions. I originally felt the "fool" when I asked people to repeat really basic things that I didn't quite catch. But over time I've learned people's re-articulations and elaborations have been one of the best ways I've learned things and identified new areas.
FWIW he's quoting the final words of the Whole Earth Catalog.
The Harvard Library Innovation Laboratory is looking for somebody. We're new. We're trying to reimagine libraries through tech. It's a cool opportunity to join a good team.
Re Architecture -
Herman Hertzberger's Lessons for Students in Architecture teaches you how to see/think as an architect does. Was the most important book I read in arch. school. It's a very personal, and generous, tour through the buildings that have been most influential to him; he points out specific moments and moves in these buildings. It's brass tacks. http://www.amazon.com/Herman-Hertzberger-Lessons-Students-Ar...
And another vote for Pattern Language. Take it out of the library just to see how the thing is written, won't take long to see why software folk cite it.
FWIW he's quoting the final words of the Whole Earth Catalog.