Imre Lakatos

It would be wrong to assume that one must stay with a research programme until it has exhausted all its heuristic power, that one must not introduce a rival programme before everybody agrees that the point of degeneration has probably been reached.

Everybody knows how fallible memory can sometimes be. You remember certain fragments precisely, but as soon as you try to join the fragments together, for a story, there is a certain - not falsification, but a shifting.