For me it would be inhibiting to write fiction based on real life events. You'd always be worrying about what the real people thought about it, and constricted by what really happened. Real life is so random, it's rarely the stuff of good story telling. Just because something 'really happened' doesn't make it more interesting or valid on the page. If anything, the opposite seems to be the case.
But. But, but, but. It's disingenuous to claim that it's all made up. In truth I'm the central character, and every other character too. Sometimes I indulge in the aspects of my personality that I don't usually display, sometimes I try out aspects I don't think I have. One of my favourite characters is the horrible George in Adultery for Beginners - oh, how I loved being him, he has no redeeming features whatsoever. I use my experiences as background: I did garden history as part of my degree, cue Anna the garden historian; I spent time in Rome as a student, cue Natalie's escape destination.
I wouldn't want to write about my life because, for the most part, it's neither dramatic or particularly interesting. I had a happy childhood that I can hardly remember and my adult life has been fairly stress free. Joyce apparently described fiction as being autobiographical fantasy, which I like as a definition. Because, although I am making it all up when I write, it's also all about me, me, me.