QED: The Strange Theory of Light and Matter

I read the book without taking breaks. Yes, I had my meals and slept. It took 21 hours. The first two lectures were easy and entertaining. The third lecture really took off. And very difficult to understand. I did not expect to understand the fourth lecture. Thanks Feynman.

Really great book to enlighten the natural forces with the help of fundamental particles. And understand day to day natural phenomenon with particle nature of light.