Sometimes the best things about a movie are the questions it raises and the way those questions stay with you after seeing it. In I Am Sam, Sean Penn portrays a mentally-challenged single parent trying to raise a daughter. Although there’s no doubt about the man’s love for his child, a social worker becomes concerned about whether or not he will be able to care for her as she grows older. Should the little girl be taken away from the father and placed in a home with normal parents? If so, what impact will this separation have on the child? Even after watching I Am Sam all the way through, which wasn’t easy, I’m still puzzled about how to answer these provocative questions.

A serious movie glossed over with Hollywood sentimentality, I Am Sam features heart-tugging performances by two-time Oscar-nominee Penn (Dead Man Walking, Sweet and Lowdown) and delightful newcomer Dakota Fanning as Lucy, the 7-year old in question. Fanning, with her baby-doll looks and precocious attitude, captured my full attention in all of her scenes. This talented youngster almost stole the film from such veteran actors as Penn and Michelle Pfeiffer (What Lies Beneath), who plays a frenetic lawyer trying unsuccessfully to combine motherhood and a career.

Pfeiffer’s character bothered me a great deal during the first part of I Am Sam. While watching her I couldn’t help thinking, "If someone like this woman can’t handle working and raising a child, who can?" Not to worry. Reminiscent of so many other films where normal people learn from the mentally-challenged, (Charly, The Second Sister, Rain Man, etc.) Pfeiffer becomes a calmer, more competent attorney and parent as a result of her relationship with the good-hearted Sam (Penn), who bugs her, of course, but ultimately charms her. Reluctantly, she agrees to help Sam convince the system that Lucy belongs back with him, not in foster care.

Despite his slow speech and lack of intellectual capacity, Sam does the best he can. He’s cheerful at his Starbucks job, telling each customer, "That’s a very good choice," no matter what the order. Every night, Sam reads out loud to Lucy from his favorite book, Dr. Seuss’s "Green Eggs and Ham." And he’s surrounded by a group of helpful, devoted friends, including his agoraphobic neighbor (Dianne Wiest, gently magnificent in her limited time on camera).

Because I wanted to know how realistic the problems and behavior depicted in I Am Sam were, I asked my daughter --- who works in an agency dealing with adults like Sam. Insisting this movie represents an excellent case study, she plans to suggest using it as part of an in-service program for her organization.

Nevertheless, I think the film contains a few glaring dramatic faults. Although Penn projects all the appropriate mannerisms and touched me deeply in a couple of scenes with Fanning, I couldn’t forget for a moment who he was. It’s not because he’s a famous star. I had no difficulty accepting him completely as the Death Row inmate in Dead Man Walking. Nor did I experience similar trouble with Dustin Hoffman in Rain Man or Giovanni Ribisi in The Second Sister. Both of these actors got inside their roles and literally became the mentally-challenged characters they played. Not so with Penn’s Sam.

Another disappointment for me was that practically everything about Sam’s friends comes across as too cute and condescending. In one ridiculous incident, they each ask for balloons from the clerk after helping Sam buy Lucy a pair of new shoes! A darling visual, but it just doesn’t ring true. Finally, the courtroom sequences seem to get out of hand. Although Pfeiffer usually wins my admiration with her outstanding performances, her credibility suffers here by exaggerating a flustered demeanor while arguing for Sam’s rights.

Does I Am Sam have a happy ending? Depends on your point of view. As for me --- I’m still wondering.

(Released by New Line Cinema and rated "PG-13" for language.)