For me, the source material can come from anywhere. It can be a poem, it can be a dream, it can be a movie, as long as the end part of it is interesting - that's what it's about for me.
If you have an anecdote from one source, you file it away. If you hear it again, it may be true. Then the more times you hear it the less likely it is to be true.
We shall find in our troubled hearts, where discord reigns, two needs which seem at variance, but which merge, as I think, in a common source - the love of the true, and the love of the fabulous.
If you have an embarrassing story, and it's a source of shame, keeping it in just compounds the shame and turns the story into something poisonous. And if someone knows about it, then it can be used against you.