Chris Brown joins the long-storied tradition of artists threatening to retire, today. In the wake of his latest arrest, Brown has taken to Twitter to threaten to quit music after his next album.  In a series of cryptic tweets, Brown lamented the fickle nature of fame and people's continued fascination with the "mistakes" he made as an eighteen year old, one of which was his infamous 2009 assault of then-girlfriend, Rihanna.