The seven ages of man are not described by "the persona of Shakespeare", but rather by Jaques, a character in Shakespeare's play As You Like It. Jaques was what was then called a "humourous man" which did not mean that he was funny but rather that he had certain persistent personality traits. In Jaques's case, he was perennially depressed, cynical and pessimistic. There is no reason to think that Jaques might have been a Shakespearean self-portrait; indeed, Shakespeare was so reticient about himself that it is highly unlikely that he would ever create a character which was a self-portrait.
