It’s hard to believe, but DA Pennebaker would have celebrated his 100th birthday today. He left us six years ago, right after his 94th turn around the run.

Besides your parents and teachers and adults you grew up with, there are few people you can point to who changed your life. Penny, for me, is at the top of the list. In 2002 we debuted a documentary he co-directed with his wife, Chris Hegedus, called “Only the Strong Survive.” It was a hit in Sundance, Cannes, and Telluride before it had a theatrical run.

When I met them in 1999, Chris and Penny were very famous for a movie they made together called “The War Room,” an Oscar nominee. During his illustrious career, Penny was a legend for two of his music documentaries that changed the culture: “Don’t Look Back” and “Monterey Pop.”

For the former, in which he followed Bob Dyla, Joan Baez, and Donovan as they broke into the greater consciousness, Penny accidentally invented the music video. H filmed Dylan tossing large cards with lyrics to the song “Subterannean Homesick Blues” played on the soundtrack.

How often has this been imitated? You can’t count. There’s a commercial playing right now that mimics “Love Actually,” which was inspired by “Don’t Look Back.” It never ends.

For his landmark films — including an extraordinary visit to the White House to film John and Robert Kennedy — Penny invented whatever he needed to create cinema verite — including cameras. He converted a 16 mm Auricon camera to make it more mobile for shooting his cinema verite. This involved attaching a grip handle to the front of the camera to make it more mobile and less cumbersome for balancing on the shoulder.

Penny used that camera in 1965 for “Don’t Look Back,” and he was still shlepping it around in the summer of 1999 when we went to film at the Westbury Music Fair on Long Island. The great Motown singer Mary Wilson had agreed to be part of our film but her clueless manager didn’t approve. Mary and her singers performed on a turntable stage while the manager chased 74 year old Penny, trying to stop him. We still laugh about it now. Penny got all his shots.

He was a great and generous teacher. It took two years to make “Only the Strong Survive,” from 1999 to 2001. I’d sit with Chris and Penny in the editing bay for endless hours, making suggestions but also overwhelmed. I’d say, “Penny, thanks for making this movie.” He’d reply, “It’s your movie, you’re making it. I’m just watching.”

I could write a book about our time together. Two weeks before he died, Penny — and Chris and I — got to spend a magical day together. Penny — who had suddenly gotten older after a lifetime of bathing in the fountain of youth — and I sat and talked about his amazing life. We were at a picnic table high on a Northampton cliff facing Shelter Island across the bay. It was bright and sunny, birds flew and chirped around us. The air was crisp. I didn’t realize this was our exit interview.

Just to go back to the 85th birthday. I arrived at Penny’s daughter’s house in East Hampton where a family picnic was underway. I said, “Penny your birthday present is coming. It’s Aretha Franklin.” Of course, no one believed me, but a few minutes later Aretha — dressed to the nines — arrived with her boyfriend, bodyguard, and sister-in-law in tow. She was so impressed as Penny rattled off his encyclopedic knowledge of jazz, blues, and soul. It was a moment no one who was there will ever forget.

Happy Birthday, Penny. I always knew I’d miss you a lot, between the hilarious malapropisms and the recommendations of New Yorker articles, and sitting around listening to apocryphal stories that couldn’t have been true but were most definitely – or thereabouts. You inspired so many that there’s a Facebook club called “Memories of Penny.” It’s filled every day with posts that make sure you will never be forgotten.