If you were asked what you learned from a list of people you could recall to any extent, could you give an answer for each of them? It doesn’t have to be something new, good, or useful that you learned from them, necessarily, just something. Can you?
Do you know of anyone good at something, but who isn’t putting that skill to use as well as it could be? Are you good at anything that you’re not putting to the best use? I think if we thought hard, we would be able to find examples of both. Some who may not be so judgmental of others may be challenged to find examples in others, but I dare say if you couldn’t find examples for yourself, you should either think harder, or go get tested for a number of psychological disorders.
Have you ever proved something nonchalantly, like it was just some routine thing to be done? If so, how did that compare to when you proved something with emphasis?