"I found Robert A. Heinlein in back issues of Astounding, and also in The Saturday Evening Post, and I read everything of his I could find. I was completely hooked on his "juveniles": Space Cadet. Red Planet. Starman Jones. Between Planets. Farmer in the Sky. Wonderful stories, and the only thing "juvenile" about them was that he took the trouble to explain what was happening. Robert once told me that young people want to know how things work, and you can tell them more in a "juvenile" than you can in an adult novel. In any event I devoured everything of his I could find, through high school, the army, college, and I couldn’t have cared less that many were "juveniles". They were wonderful. I met Robert Heinlein years later, and through some kind of rare magic we became instant friends. We corresponded for a decade. In those days I was an engineering psychologist, operations research specialist, and systems engineer in aerospace. Most of my work was military aerospace, but I did get to work on Mercury, Gemini, and Apollo. We were helping to make the dream come true! I went from there to a professorship, and then into political management and city government. Robert visited me when I was working for Mayor Sam Yorty. "You probably don’t know this," he said, "but my political career ended when Yorty beat me for the Democratic nomination to the State Assembly." When I finally decided to get out of politics, academia, and the aerospace industry and try my hand at writing, Mr. Heinlein was enormously helpful. Years later, when I was an established writer, I asked him how I could pay him back. "You can’t," he said. "You don’t pay back, you pay forward." I never forgot that, just as I never forgot the wonderful things his ‘juvenile’ stories did for me."