> Often things go well at first. I’ll feel I can sketch the basic claims, paint the surface; but when someone asks a basic probing question, the edifice instantly collapse

That to me doesn't sound like someone complaining about not remembering what they read, but someone complaining that they can't backup the arguments that they now consider their own. Books aren't meant to transfer the author's knowledge to the reader they're meant to offer an abstraction of the author's knowledge to the reader.

The writer of this post has no trouble remembering the abstraction, but without more effort the abstraction cannot be backed up.

In order to really make knowledge your own you have to do serious work. You can't just read one book.

The proper conclusion from that is that the book is bad. If you are reading fourth similar book and all sux proper conclusion is that I need to select books differently. Or read to learn differently. (Because most reading is not to learn).

If we were in situation where many people rarely learn from books then conclusion would make sense. But authors examples are all fairly in same category - pop famous edutainment. Maybe selfish gene sux at teaching. But it is apparently good entertainment and did a lot to popularize that part of biology and evolution. It worked in that sense for many people.