People do tell a writer things that they don't tell others. I don't know why, unless it is that having read one or two of his books they feel on peculiarly intimate terms with him; or it may be that they dramatize themselves and, seeing themselves as it were as characters in a novel, are ready to be as open with him as they imagine the characters of his invention are.
The Razor's Edge (ed. Vintage, 2011) - ISBN: 9780307785084