trivialist

noun

1. A proponent of trivialism, the metaphysical and logical theory that all propositions are true.
2. (rare)One who is interested in trivia or trivialities; one who is familiar with the small details of a particular subject.

   “There were many groups that flourished during the fifties, and rock trivialists love outdoing each other by naming the most obscure songs, groups, and labels they can think of.”

   “Walter was a very friendly man and a very intelligent man. He was a good conversationalist and a trivialist. His pockets were stuffed with different trivia that he liked to test the rangers with.”