I think the author is too hard on themselves for not knowing things, probably coming from shame. I can only speak for myself but learning to shrug that off just how to say "I don't know X" or "I forgot X" is very freeing. I say I don't know shit all the time at work, and so do people I work with. We aren't encyclopedias. Just chuckle about it and figure it out and learn.
I much prefer working with people who can just be honest about what they don't know, it's way better than pretending to know or trying to save face, and generally people in the former camp seem to have higher EQ.