LIFE AND HOW TO SURVIVE IT By Robin Skynner and John Cleese (Methuen, $288) WHEN I worked in the theatre I was warned that the people on the actual performing side of the business usually combined great personal beauty with the odd missing screw in the head.
This is probably unavoidable. What completely sane person would wish to earn a living by emoting ostentatiously before an audience of complete strangers? Now here we have John Cleese, scarred veteran of the hit British comedy series Fawlty Towers and numerous Monty Python enterprises (''This is a dead parrot...'') offering a book on what is basically, in the deliberately down-market language used throughout, about ''keeping your head together''.
I do not know much about Mr Cleese's private life but what little has emerged in public does not suggest a man with the secrets of human happiness at his fingertips.
Mr Cleese is more in the tradition of concealed despair under the motley which runs from Pagliacci through George Formby to Tony Hancock and Peter Sellers.
Would you buy a used relationship from this man? But just a minute. We also have Mr Skynner. Mr Skynner is responsible for most of the book. As it is written in the form of a dialogue between ''John'' and ''Robin'' I can say this with unusual confidence.
Mr Skynner is a family therapist. This means he belongs to the modern school which no longer believes your problems started when you first discovered that your father had a penis (or that you didn't) but still traces your problems back to roughly the same time.
