Which edition are you reading? The original from 1973 or the 1984 reprint? I read the 1984 edition that same year when I was a teen, and I remember Gerrold writing in that version how there were differences from the original. In several places, he wrote, "In the 1973 edition of this book, I wrote about.....". I've been curious about the 1973 printing ever since, but every copy I've found has been priced beyond my budget.