In the introduction to her authoritative biography of Shostakovich, published in 2000, Laurel Fay sounds a sharp warning about the historical value of personal reminiscences:

Fascinating and useful as these can be, memoirs furnish a treacherous resource to the historian. Reminiscences can be self-serving, vengeful, and distorted by faulty memory, selective amnesia, wishful thinking and exaggeration. They can be rife with gossip and rumour. The temptation to recast the past to suit the present . . . can be hard to resist. In any case, factual accuracy is not generally one of their most salient features.

LRB 21 June 2007 | PDF Download