For anyone who suspects (or has figured out) that much of what is commonly understood to be The Truth About Life is actually a series of mistakes, lies, and fantasies, the film “I Am” is a powerful affirmation that we’re onto something. Director Tom Shadyac used to be Director: Tom Shadyac, the auteur of big-budget Hollywood comedies starring Jim Carrey and Eddie Murphy. Addicted to more of everything, Shadyac acquired and consumed and wondered why the hole he was trying to fill never seemed complete. After a serious illness, he switched paths. “I Am,” made with the craftsmanship of an old pro, chronicles Shadyac’s exhilarating journey toward enlightenment. Desmond Tutu, Howard Zinn, and Noam Chomsky are some of the thought leaders interviewed, along with a menagerie of brilliant authors and scientists speaking plainly and clearly. What they — and the New Tom — conclude is…what you already know deep in your heart.