The history of the apple is too absurd. Whether the apple fell or not, how can any one believe that such a discovery could in that way be accelerated or retarded? Undoubtedly, the occurrence was something of this sort. There comes to Newton a stupid, importunate man, who asks him how he hit upon his great discovery. When Newton had convinced himself what a noodle he had to do with, and wanted to get rid of the man, he told him that an apple fell on his nose; and this made the matter quite clear to the man, and he went away satisfied.
source
Carl Friedrich Gauss, as quoted by Robert Chambers, "Sir Isaac Newton and the Apple," The Book of Days (1832) [https://books.google.com/books?id=K0UJAAAAIAAJ Vol. 2], p. 757.