"There's an essence of Tommy that I didn't realize was as elusive as it is. And I think finally when I started watching the first movie over and over and over, things started to click a little bit," he said.
The idea of joining a winning big budget franchise left Brolin both exhilarated -- and a little bit scared.
"Yes it was abject fear that I was feeling in the beginning. And I wanted Tommy to like it, and I wanted, you know, you want your friends to like. It's a prospect that's not the most…probably not a great career move on my part, you know what I mean? Just the idea of doing something that could have failed miserably. So I'm just glad I didn't get in the way of the movie, I'm happy about that," Brolin said.
For Brolin's role, the film is set in 1969, which was fun for him to experience. In real life, he was only 1 year old at the time.
"1969 was a fun time wasn't it? At least colorfully in the movie it's a really good time," he said. "It's an era, I would have loved to be able to experience, and not as a 1 year old and crawl through it. I would have liked to run through it."
You can do some time traveling with the "Men In Black" when it hits theaters May 25.