When I was a boy, our advanced math teacher said (something to the effect that) only a handful of people understood Special Relativity when Einstein first came up with it.  So I had the impression that Special Relativity is something difficult to understand.  But thanks to this book by Feynman, I think anyone can understand Special Relativity with a little effort.  (It's probably easier for people with high school math, but I suspect it's possible to understand Special Relativity even without high school math.)<br><br>That said, I do have some background in high school math, and I read the book twice. (Making written notes the second time.)  And admittedly, I probably haven't understood everything about Special Relativity.  But I do feel that I understand Special Relativity enough to be able to explain what it is (and why it's true) to someone else (who is interested).<br><br>Thank you, Mr Feynman, for taking the trouble!  And thank you to the editors and publishers for making Mr Feynman's work available to the general public.