I think Mike's lecture had several points:
1) We don't know everything. This is a platitude, yes, but Mike's great experiences and strong storytelling style humorously drives this point home.
2) Dirty jobs get the short end of the stick, whether its in media, or the way its shown in culture. Skilled labor is important, and should be given its own space instead of looking down on it. I bet Mike wanted to say something about university vs trade school and etc.
3) Reminding people that while it is great to venerate the creators, innovators and etc, you need the back-end to support the front-end. As eloquently as he puts it, "innovation needs imitation".
Also I learned about peripeteia and an agnorisis. Put a little more culture in my life.
FWIW, I saw this a long time ago. I haven't forgotten his story or his message since.