Oscar-winning actor Gary Oldman starred in the Harry Potter movie series as Sirius Black, and the actor credits the role with making him a better father. But Oldman didn't love everything about the Harry Potter series. On the Happy Sad Confused podcast, Oldman said his performance in the films was "mediocre."
"I think my work is mediocre in it," Oldman said. "No, I do. Maybe if I had read the books like Alan [Rickman], if I had got ahead of the curve, if I had known what's coming, I honestly think I would have played it differently."
"It's like anything, if I sat and watched myself in something and said, 'My god, I'm amazing,' that would be a very sad day, because you want to make the next thing better," he said.
Also during the interview, Oldman revealed what he thought was the hardest scene to film in the Harry Potter series. He said this was the scene in Prisoner of Azkaban when he's lying by a frozen lake, with his soul leaving his body. Oldman said this took about a week to film, and all the time, he was just lying down and getting very cold and uncomfortable. "The hardest thing I had to do was lie next to a frozen lake," he said.
Interview on: https://www.youtube.com/watch?v=pAO2y3kqkl0