//Some modest spoilers ahead, just in case you still want to read it and haven't taken advantage of the 61 years since it's publication.
I had forgotten almost everything I knew about Arthur C. Clarke's Childhood's End.
I did remember hating the ending, doubtless for the same reasons that I still hate it.
That said, the theme is a fascinating one, the notion of transcending humanity. It's an age old dream, almost as old as human records. If such diverse characters as Kurzweil and Harari are right, that possibility lies right before us. Perhaps man can become superman, and not by magic or the supernatural. We are already in a sort of cyborg transition, as our ubiquitous electronic appliances become ever more integrated into our existence. It's hardly implausible that some kind of phase change in human nature is at hand, and that our descendents two or three (or four or five) generations hence may become unrecognizable to us.
Back to Clarke's book though, it really is amazing how prescient he was in so many ways.