Claude Montpetit -- Montpetit.net -- en

Tim bray presents his two laws of explanation:

1. When you’re explaining something to somebody and they don’t get it, that’s not their problem, it’s your problem.
2. When someone’s explaining something to you and you’re not getting it, it’s not your problem, it’s their problem.

...

This [the second law] actually turns out to be pretty hard; a lot of people, in particular young people, find it painful to admit they don’t understand. When, sometime in my thirties, I realized that I had enough experience and accomplishments that if I didn’t get something it was OK to just say so, my quality of life got way better.

Tim's series entitled Technology Predictor Success Matrix is also worth reading.