Roger Zelazny: "This Immortal" ( aka "....And Call Me Conrad")
I really enjoyed this. I can see how it tied for the 1966 Hugo Best Novel with "Dune" despite being much much shorter. Most impressive for a first book. I was particularly taken with how little background information/world building there is. You learn nothing other than what comes up as the plot develops, and that really works. This could so easily be turned into a 500 page doorstop.
A while back I got rather tired of the Zelazny heroic alpha-male, but, perhaps because I haven't read him in a while, I was very much intrigued by the main character.
I was also somewhat mortified to find that, despite having read and very much liking "...And Call Me Conrad" around ten years ago, I remembered absolutely nothing of the story or plot-line other than recognising, when it appeared briefly, a certain mutated animal that lives in the Nile.