I have his 'Six easy pieces' and 'Six not so easy pieces' but do not have the lectures. However, my go-to book on the subject is 'The Road to Reality' by Roger Penrose (2004), which pretty much defines the state of physics prior to the discovery of the Higgs particle and the detection of gravitational waves, both of which confirmed, rather than expanded, existing theory.
I was about that age when I discovered it. I really enjoyed it, possibly because I was too naive to see the darker truths underlying Heller's humour.
Catch 22 took me the longest to read of any book I've ever finished, except perhaps War and Peace. We did The Mayor of Casterbridge for O Level. Still not got past Chapter 2, I found it unreadable. Brodie's Notes saw me through the exam in comfort. Ulysses - my dad used to quote passages. I got about 3 pages in and gave up.
Just checked eBay £1.99 free post so won’t break the bank. First copy I looked at was two quid plus three pound seventy postage!
Mention of Feynman reminded me of his autobiography, which is a great read. Similar are the writing of Neil deGrasse Tyson. A mixture of humour and physics is always strangely attractive to me.