Though it sometimes feels like an extended parlor game of trivia, "Unforgettable" is a playful and humorous documentary about Brad Williams, a La Crosse man with incredible memory.

Almost everyone knows someone who has a great memory and seems to remember more about their lives than the average person.

For many people in La Crosse, Brad Williams is that person to the nth degree -- he can remember almost every remotely significant personal event or current event from his lifetime, what date it happened and what day of the week it was.

In the documentary "Unforgettable," which played Friday night at the Monona Terrace as part of the Wisconsin Film Festival, Williams' brother Eric captures his brother's rise a few years ago to morning talk show fame as a result of his gift.

The movie starts from the point when Brad Williams learned that his memory is not just very good, but truly exceptional -- in 2005, researchers published an article about a woman with a similar memory, calling the condition "hyperthymesia."

After getting in touch with researchers, Williams is confirmed to be only the second known case of it. That number has since risen to seven, but the uniqueness of his abilities remains impressive fodder for the documentary, which features clips of Williams' talk show segments, interviews with him and his family, friends and scientific researchers and perhaps most notably, a personal meeting between Williams and famous Jeopardy champion Ken Jennings.

Brad Williams is a likable protagonist and surprisingly normal, and there is a special level of comfort and playfulness in the movie that only a brother could capture. Both brothers, but particularly writer and director Eric, have a strong sense of humor that pervades the film with a refreshing sense of sibling camaraderie.

The camera work is solid but rarely exciting. Much of the film consists of interviews at offices or in the back of cars, spliced to great effect with home movies and newspaper clippings.

Sometimes, however, a striking shot of the brothers' travels to New York or California will flit across the screen, and during one memorable scene when an expert discusses the expected shortfalls of having a brain like Brad's, such as not being able to tie one's shoes, the camera humorously pans to Brad's laceless loafers.

The main trouble with the film, however, is that the lack of knowledge about Brad's condition -- how it works and what potential benefit its study will provide -- makes the film feel like an extended parlor trick at times, a large collection of scenes where Brad correctly or very nearly pinpoints dates in his life. While Brad's ability is truly impressive, prompting gasps or snorts from the audience, it won't cure cancer and much of its current benefit seems to be toward Brad's family and co-workers, who rarely have to remember anything on their own.

But in the Q & A after the film, the Williams brothers said that University of California-Irvine researchers may have found something in Brad's brain and others like his that could provide some insight into why their brains work differently and arguably better than the average one. Publication of the study is pending, and thus it could not be included in the film.

As many scientists in the movie pointed out, studying Brad could potentially provide some key insights into how facts are stored and retrieved in the brain. Until then, however, Brad's brain may be most useful to the good people of La Crosse.