Because of when most of his (best) stories were written you have to consider the date of creation before reading. Door into Summer is a good book but it was written in about 1957, part of it takes place in 1970 and part takes place in 2000-2001. Obviously it is out of date but in 1957 it was very innovative. Other books, such as Double Star, are not dated.

I got my start reading Heinlein in the 1950s. I still enjoy reading him today.

Robert Heinlein was my favorite writer growing up. I agree with a lot of people "that the door into summmer" was his best work, but when you get a chance you should the read "Beyond this Horizon" which was remarkably ahead of its time for its realease in the 1940's. Like a lot of Heinlein novels, it dealt with social engineering, but the genetic enginneering angle was really cutting edge.

I like "The Door into Summer" as well, but an added bonus for me is that it is the only book I know of where I have the same name as the main character.

Without giving too much away: What is Stranger in a Strange Land about?

Iron Maiden has a song by that title and a lot of their songs are based on literature. Just wondering if they were related.

(They also have a song called Number of the Beast, which I know is not based on Heinlein's).

I finally have time to read books again so I may have to check out some Heinlein's work.

SiaSL: Earth astronauts went to Mars, two of them had a baby; the astronauts died on Mars and the baby was raised by Martians. He is then later [20 years or so] brought to Earth by another set of spacefarers, and the book details his life on Earth [as a Stranger in a Strange Land], how Earth and Earthlings affect him, and how he affects Earth.
As such a lot of it is certainly commentary on Earth society at the time, along with possible alternatives.
OT: That's one thing I like about Iron Maiden, they are a very literary and knowledgable band. My son's middle name is Alexander, and I've played Alexander the Great for him multiple times. ["Do you want to hear the song about the king with your name?"]