I started reading SF many years ago when they lumped Fantasy & Horror into the SF group. I never really liked Horror nor most fantasy even though sometimes it is difficult to tell the difference between the three. The reason I started with SF was, in college on a very tight budget, my entire entertainment came from borrowing my brothers books. He read either SF or "Hornblower" & I just couldn't get into the Hornblower series.
Some time later when thinking of my favorite authors (Heinlein, L'Amour and Jean Auel) I realized that I like well-told stories about people. Each of these authors fit that category.
In the old days, before Star Wars and Star Trek, it was easier to find a good SF book since SF writers (writing to a smaller set of readers) had to be good just to survive as a writer. This made it much easier to walk into a book store and quickly find a few good books to buy.
Today the Internet and ebooks makes that criteria somewhat obsolete.
