A psych professor at a Boston community college, Sean Maguire can barely hold the attention of his students. But there’s a bright, if unsatisfied, mind at work inside of him, one that is tested and challenged when he agrees to meet with a troubled young man who just happens to be a once-in-a-generation genius. Robin Williams (in glorious full-beard mode) lets audiences see the loneliness that threatens to consume and paralyze the part-time therapist. Maguire sees more than a bit of himself in Will (Matt Damon): they’re both gifted but under-achieving Southies. Their sessions — which begin with the tense energy of two prizefighters circling one another in the ring — lead to each finding out a lot about each other (and themselves) and, of course, ends with a memorable breakthrough moment that caused many a man-tear to be shed.