"For me as a parent, the important part was to get the information out, because I feel like you just have to know," Will Smith said at the Concussion premiere Tuesday

By Jodi Guglielmi and Scott Huver
Updated November 11, 2015 05:40 PM
Kevin Winter/Getty

When Will Smith signed on to film Concussion, even he admits he was naive about the potential risk of head trauma for football players.

But when Smith learned some of the statistics behind the case of Pittsburgh Steelers center Mike Webster – whose story is depicted in the film – he was shocked, and realized just how important of a story it was to tell.

In the film, Smith plays Dr. Bennet Omalu, who discovered chronic traumatic encephalopathy (CTE) in the brain of Webster as well as other football players. Omalu went on to claim that professional football could pose a long-term threat to the health of players who repeatedly suffered head injuries.

“One of the statistics in the film is that by Doctor Omalu s calculation, Mike Webster sustained more than 70,000 blows to his head from the time he was a young man through high school and college, and then an 18-year professional career,” Smith told PEOPLE at the AFI Fest gala premiere for Concussion Tuesday at the TLC Chinese Theater in Hollywood.

“The thing that was a revelation for me with this is that it’s not really the big hits that are the problem, but more of the issue is the repetitive head trauma,” he added.

Once Smith, 47, began working on the film and speaking with Dr. Omalu, the actor who calls himself a “football dad” quickly found the message hitting home.

“Some of the best times I ever had with my oldest son were on that football field,” Smith told reporters. “It was such a revelation for me. The big thing was I had no idea. I had no idea the potential issues of head trauma. That’s not what I was worried about.”

Smith said that the “revelation” he felt solidified his reasons for doing the film and inspired him to help spread the message.

“For me as a parent, the important part was to get the information out, because I feel like you just have to know.”