The way in which he views the world, analysed it and obsesses about solving problems.
I was "diagnosed" with autism by the elementary school's shrink and put in a class full of autistic children. Very similar to the kid in the video.
I certainly liked to think and speak when I was his age. However, I did not possess such energy or that disturbing laugh.
-Duxwing
The laugh was because he is a nervous public speaker. Making a joke when you're a public speaker and if you don't know whether or not your audience will find it funny, is absolutely nerve-racking for some.
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I went to a BBQ yesterday with my old friends from the previous city I use to live in. Most of them are mathematicians or physicists. Being with a group of people with the same interests and passion as I was quite liberating. It is not too often I am with a group of people who appreciate novel ways of making pattern recognition algorithms more computationally efficient.