Red Planet and
Citizen of the Galaxy are probably two of the earliest science fiction novels I ever read, around the time I was eight or nine years old. I moved on to more "adult" science fiction fairly quickly, encouraged by my dad who was a science fiction fan from way back. But they really were formative for me. "Gateway drug" indeed.
Actually, I've probably read more of the books on the list than that, but these are the only two I remember at all.
Red Planet encouraged me in my early determination to be the first female on Mars. Then I figured out that you had to do math to be an astronaut - I was crushed. And
Citizen of the Galaxy enthralled me with the idea that a person so young could be set adrift alone in the universe. I could see both the drawbacks and the advantages of that eventuality, and they provided endless fodder for daydreams as a child and adolescent. Sometimes even for the adult me.
