Lessons learned in school can stick with students for years.

We asked Nat Geo staffers to share one idea that resonated with them, and here’s what they had to say:

Photograph by Michael Nichols, National Geographic

Photograph by James P. Blair, National Geographic

Photograph by Richard Nowitz, National Geographic

Photograph by Michael S. Yamashita, National Geographic

Image courtesy Peter Spirer

Photograph by Thomas J. Abercrombie, National Geographic

Did we surprise you? Chime in with your thoughts! Tag your posts on Facebook and Twitter with #TeachNatGeo to share something you learned in school that completely surprised you.