My Life Story and the Famous People Who Are In It!

Dear Rich: I am in the process of writing my life story and how several well-known celebrities touched my life. How they came into my life, used aspects of my life to build their "persona" and labels, used in published works of art (books, music and movies), is a story with which they would not want told. Many family and friends have suggested that I fictionalize and I have considered writing in Roman a clef. Despite the fact that they are public figures, is it not my right to tell the true story with proof (names of family and friends, letters, documents, birth certificates, and pictures) of what they chose to draw from? Also, what legal issues may be raised in doing so? Did you ever stop and think that really, what's the difference between a famous person and a non-famous person? It's just a matter of who stumbles into the spotlight and how long they stay there. We bring this up because, as we'll explain, it's easier to get away with stretching the truth about public figures than it is with the rest of us little people. 
"Is it not my right to tell the true story?" We're not sure exactly what you mean by that. There is no basic legal right to tell one's life story (although a lot of people using cell phones in public seem to think so). There is as you know, a right to speak freely. however, but even that right comes with some caveats. 
Defamation and Invasion of Privacy. There are two major free speech exceptions when writing memoirs and autobiographies. (We got asked the difference the other day and that led to an interesting discussion.) Those exceptions have to do with (1) whether you are defaming someone (telling lies that cause harm) or (2) invading someone's privacy. Invasion of privacy comes in several flavors but generally, authors are protected as long as they are providing fact-based recountings of actual accounts. 
Public figures and defamation ... Legally, it is "harder" to defame a public figure than a regular civilian. That's because public figures are supposed to have thicker skins (must be from all that spotlight heat) and a wronged celebrity would have to prove actual malice, a higher hurdle than what's required for mere mortals.
Your author contract. If you sell your memoir to a publisher, your author contract will likely require that you defend the publisher against any claims that occur. That could be risky from a personal liability point of view ... so in that case, you may want to have the book vetted for issues like this by a media attorney.