The Golden Age by John C. Wright
Phaethon Prime Rhadamanth Humodified encounters an old man who accuses him of being an imposter and an allen from Neptune who reveals that he has had essential parts of his memory removed. THE GOLDEN AGE is a grand space opera, a large-scale SF adventure novel in the tradition of A. E. Van Vogt and Roger Zelazny (with perhaps a bit of Cordwainer Smith enriching the style). It is a thrilling wonder story that recaptures the excitements of SF's golden age writers.