I hope you watched the video through to the end.
This book is about how we are not as observant, or indeed as smart, as we think. We think we are fully aware of our surroundings, but in fact one of the things that we aren't aware of is precisely the extent to which we are not aware of our surroundings. We think we can remember specific events in full detail, but other people who were there may have completely different memories in perfectly good faith. We trust people who display confidence in themselves and their own judgement, yet in fact they are no more likely to be right or trustworthy than people with lower apparent confidence. We don't know as much as we think we do, and often we don't realise how little we know (the Dunning-Kruger effect). We mistake correlation for causation. And we believe that there may be mental tricks to unlocking our brain's full potential, when in fact the only thing that really has been shown to work for everyone is just keeping fit.
Chabris and Simons wittily and forcefully pull apart each of these illusions, fully backed by research and worked examples that you can try on yourself (and on willing friends and relatives). The conclusion is that we must be eternally vigilant, especially about ourselves.
I've had some bad luck with popular psychology books recently - in particular a couple of stinkers by Pinker - but this is much better. Recommended.