I recently stumbled upon something I didn’t know existed: the very first novel by Robert A. Heinlein that was written in 1938 and remained unpublished until 2003, long after his death. It is clear from the very first page why he couldn’t sell it to publishers in 1938: it challenges the contemporary social taboos as mercilessly as his late work, and it took becoming the most popular sci-fi writer in the world for Heinlein to be able to get back to this kind of writing.