Ask HN: What are the notable characteristics of brilliant people around you?

One of my friend who is a programmer has a really good memory, he can recollect any concept or a jargon right from the top of his head. He also has a right sense of judgement i.e he can clearly separate out right from the wrong.

Another friend of mine spends a ton of time reading and researching. He spends the day working or discussing ideas and spends the night researching about his work and learns continuously.

I admire both my friends and many more. I would like to hear your first hand experience of such people around you and their particular characteristics that you admire. Thanks!