First he sold his estate and moved to a mobile home. Then he stopped flying in private jets. He decided to accept only the Directors Guild minimum for any movies he directs.

Tom Shadyac was already on what he calls “a course of change” when, in 2007, he had a horrendous bike accident and wound up eyeball to eyeball with death.

It was enough to convert the director of “Ace Ventura: Pet Detective” into a documentarian interviewing the likes of linguist Noam Chomsky and South African cleric and activist Bishop Desmond Tutu.

It was just months after his last film, “Evan Almighty,” hit theaters that Shadyac suffered the terrible fall from his bike. Diagnosed with post-concussion syndrome, the jokester was left with a condition that was no joke, in which the symptoms of a concussion don’t go away. Something as simple as a trip to the grocery store was painful for Shadyac, whose brain was unable to filter various stimuli. After medical treatments failed to help, he isolated himself completely, sleeping in his closet and walling the windows of his mobile home with black-out curtains. “After four months, I wasn’t getting better. I wasn’t suicidal at all, but I said, ‘If this is as good as my health gets, this is it for me.’ ”

As his symptoms finally began to subside, the director wanted to share his inner quest in the way he knew best: through film.

Shadyac’s lion mane of curls gives him the air of something between a mad scientist and an aging hippie — which he’s not. But he is a prankster who had a little too much fun tampering with his high school’s morning announcements in Falls Church, and a U-Va. graduate and literary buff who casually invokes the works of Rilke, Mary Oliver, Hafiz, Thoreau and Emerson. But lately he’s simply the flawed protagonist of “I Am.”

Here, Shadyac turns the camera on himself, traveling around the country to explore the root causes of the world’s ailments and how to cure them. The question becomes, who had it right, Charles Darwin or John Lennon? Is it survival of the fittest, or is love all we need? He discovers that human beings are deeply, psychologically connected not only to one another but even to the most disparate things, from a bowl of yogurt to butterflies in Brazil.

A friend who has known Shadyac since his marauding high school days says, “He’s now become brave enough to take that conversation outside his head and into the world. Tom comes from a family of givers,” and so he follows in the footsteps of his late father, Richard Shadyac, co-founder of St. Jude’s Children’s Research Hospital. All proceeds of “I Am” will go to the Foundation for I Am, which supports a variety of charitable causes.

Shadyac says, “Through his work, my father showed us what the new communal paradigm should look like, but he didn’t think we were capable of achieving it because of the limitations of human nature as he saw it.

“I’m dedicated to telling a different story.”

Even so, Shadyac has no plans to drop the kind of films that made him a success in the first place.

“I consider the laughter inspired from, say, ‘Ace Ventura,’ a sacred act. . . . The parables we were able to tell from ‘Bruce Almighty’ to ‘The Nutty Professor’ to ‘Patch Adams’ are the ways that people have a conversation about who we are and what we’re capable of.”

Chammas is a freelance writer.

I Am

will screen at Landmark’s E Street Cinema on Sunday.