I read this novel originally when it was first published. I have been on a "journey" to reread Heinlein's novels again since I am older (and hopefully, wiser). I was not disappointed. It was as fresh as when I read it the first time. And I may read it again.
This novel is often referred to as the 2nd book in the Lazarus Long Series (Methuselah's Children, Time Enough For Love, The Number of the Beast, The Cat Who Walks Through Walls and To Sail Beyond the Sunset). Lazarus Long (nee Woodrow Wilson Smith) is the longest living member of the Howard Families. The book includes numerous short stories/tales as told by Lazarus through Justin Foote (Chief Archivist) and also includes a number of his "saying" (collected in another book as well.) Stories in the book are about events that take place after Methuselah's Children. And one about meeting his mother (and himself). It is fun, amazing, sad, and enlightening.
If you have enjoyed Heinlein's Future History novels, you will probably enjoy this one as well.