I haven't been a fan of Sean Penn's since Fast Times at Ridgemont High. Since that time, nearly all his films have left me flat. In fact, I nearly didn't watch this film since he was in it. What a loss it would have been if I'd missed it! I won't go into the story line since that's been reviewed a lot by others. The story is sort of a cliché'd one and has been done before, though not as well. The story isn't this film's strength anyway - it's the acting. Rarely have I seen a film with this much powerful acting. Penn's performance as Sam is brilliant! He must have studied autistic/mentally challenged people to pull this performance off. I also want to mention how good Michele Pfeiffer was in this. Her character starts out as a hard-hearted witch and ends up being very human, thanks to her exposure to Sam. The change in her is gradual, subtle and fun to watch. Sams friends, very well played by Brad Silverman, Joseph Rosenberg, Stanley DeSantis and Doug Hutchinson are very important support characters. Laura Dern gives a stellar performance as Randy. Dakota Fanning as Lucy very nearly steals the show. This little actress has quite a career ahead of her, I hope! This film is delicately balanced, and has a good bit of humor interspersed with parts that will have even the most insensitive of you reaching for a tissue. The film has a sort of a sappy (and somewhat surprising) outcome, but by this time any other ending would have been pretty much unacceptable to most people. This movie blew me away and I gave it a 9.