General relativity, or maybe some stuff that Ramanujan figured out? But probably other people would have eventually figured those things out if they thought about them long enough. In general I think the answer is no. There's a fascinating book called The Sociology of Philosophies that explores this question. The author's main idea is that intellectual ideas arise from competition and variation among different intellectuals who are related to each other through intellectual networks and that only ideas that are creative, but not too creative, get remembered and extended, refined, or rebutted and passed on to later generations of scholars.