Sean Penn and Dakota Fanning in I Am SamI AM SAM

How does one begin to discuss the blinding idiocies of I Am Sam? This comic weepie about Sam (Sean Penn), a mentally challenged Starbucks employee trying to retain custody of his young daughter Lucy (Dakota Fanning), is so shockingly offensive, both thematically and as a work of cinema, as to defy rational analysis, so here's a brief checklist of what made me want to bash my head in: