"People say I look older or more mature, but I think I look that way because I've been thoroughly observing the personality of my recent role."
Yoo Ah In said, "Speaking Busan dialect and performing action stunt scenes were the most challenging part of filming 'Tough As Iron'." It was difficult for him to film in Busan dialect when he was used to Daegu dialect. In addition, training for action stunts was long and exhausting.
"I'm not good at training. I'm really bad at reading too. I can't just sit around and say my lines," Yoo Ah In said, adding, "Same thing with action stunts. I do better when we're actually filming than when I'm getting trained. When I tell myself, 'This is the time to use my 100%,' my lines, actions and facial expressions become real. Thinking 'I'm going to do it this or that way' when filming seems fake to me."
He also shared what he thinks to be the charm of acting. "One of reasons I like acting is spilling all of myself as if spilling water. I used to be timid and quiet but, after becoming an actor, my personality changed a lot. When the camera reels and I start acting, I feel a lot of catharsis coming inside of me as if kicking a bucket full of water."
