Time Enough For Love is the Robert Heinlein novel that gets polar opposite reader ratings on Amazon. All 5-stars and 1-stars, little in between. Readers either love it or hate it, the latter finding it crushingly boring or take offense at the sexual framework (sex between relatives, a man having sex with female clones of himself) in which the main story is set. But all that is the back story for a series of inner stories that are quite good, and full of great thoughts from Heinlein’s Lazarus Long, a 2,000 year old man in the distant future.
I think the book is worth it for the great Heinlein quotes from Lazarus Long, even if you find the story lacking in interest. Examples:
In one of the inner stories Lazarus Long time travels back to Kansas City of 1916 to visit his parents. Heinlein’s slice-of-life realism is that of an accomplished and gifted writer.