The attached video portrays his thoughts on how people think and how differently people who seem to think similarly may in fact not.
To summarize the video Feynman describes how, as an undergraduate at Princeton, he tried to figure out how accurately he could keep time by counting in his head. (You know, the old "one thousand one, one thousand two, ..." routine.) He chose a minute as his target and basically got to one thousand forty eight as a reliable estimate of a minute.
Feynman was exploring what he else he could do while performing this counting. He realized he could read fairly well but he could not count things, for example he could not count out his socks for the laundry but he could lay them out in a pattern to count them.
Basically the counting of something besides the time confused "the voice in his head."
After figuring this out Feynman approached a mathematician at breakfast and described how the mathematician could not count something besides counting out the time.
The mathematician said it was nonsense and proceeded to demonstrate to Feynman how he in fact could count something besides the time. However the mathematician could not read something else as Feynman had.
The result of all this is that Feynman realized that the mathematician was counting time by visualizing a counter in his head while he, Feynman, was using his "inner voice" to enunciate the each "one thousand one."
To me, as a father and grandfather, this was something of an epiphany.
I have often wondered why one child could easily learn something while another child could not.
It never dawned on me that one child might visually see something while another might hear it instead.
More importantly why had no educator, ever, that I had crossed paths with over the last thirty years ever mentioned or thought of this.
One child sees the word visibly as in image in their mind, another hears the word being spoken.
And no doubt there are other ways this could be done as well, say color (see "Born on a Blue Day" by Daniel Tammet").
Now just sorting out people who think with images or sound or something else might make everyone's life (parents, teachers, etc.) easier. Tammet in particular knew himself how different his model of thinking was from everyone else...
As a parent and grandparent I have watched children inexplicably struggle to understand things that seem quite obvious. I've always wondered why they struggled. This offers a glimmer of hope in understanding why...
And still, no educator has ever even suggested that any two children learned differently (see "Teaching Your Child" I wrote about five years ago).
In fact they think just the opposite...
That all children are the same in this regard.
It really makes you wonder what they learn in school about education and the principles of teaching.