A liar's autobiography

This British comedian and Monty Python member (Chapman having been described by his writing partner John Cleese as the "best actor" of the bunch) has produced an alleged autobiography that is so convoluted and unbelievable that my best guess is that it is only 10% true. Michael Palin, also a Python alumnus, claims the book is a combination of the Magna Carta and "Valley of the Dolls". Python member Eric Idle claims that it took four people for one comedian to claim to have completed the project. Chapman himself claims on page 80 that although "the names have been kept the same, the facts have been altered...". Appearing first in 1990 (the back cover blurb claims 1980 on an edition that clearly notes 1990 in the copyright credits) and reprinted several times since then, this is probably NOT an autobiography. But it is quite interesting.