"Brandon Sanderson" is the pen name of Alcatraz Smedry. His Hushlander editor forced him to use a pseudonym, since these memoirs are being published as fiction

Alcatraz actually knows a person named Brandon Sanderson. That man, however, is a fantasty writer, and is therefore prone to useless bouts of delusion in literary form. Alcatraz has it on good authority that Brandon Sanderson is actually illiterate and dictates his thick, overly long fantasty tomes to his potted plant, Count Duku.

It is widely assumed that Brandon went mad several years ago, but few people can tell because his writing is so strange anyway. He spends his time going to science fiction movies, eating popcorn and goat cheese (separately) and trying to warn people about the dangers of the Great Kitten Conspiracy.
He had his library card revoked on seventeen diffrent occasions.