Truth is stranger than fiction.
Even fictitional authors draw from life experience, they just don't put 'real' names to the experiences. I personally think that putting pen to paper is so difficult and emotional at the time - but a form of release on completion. Sort of self-counselling, it gets it out of one's system. Something like writing a diary and looking back on it years later and remembering those feelings at the time, it helps to move on. Publishing the work must take courage and the resultant criticism is to be expected.