In the preface to the 4th or 5th book (which were written 30+ years after the “original” trilogy) he discussed how the originals parts of the trilogy were published as a set of short stories in a SciFi publication over 8 years, and later compiled into the books.
I was astonished.
Perhaps everyone else already knew this. But such a clear narrative through line to be written in discrete short stories. Very impressive.
It sounds like this may have been common prior to this era as well.