He definitely took acting seriously when he was young, worked hard and was passionate about it. The one story about the “I coulda been a contender” scene in “On the Waterfront” where he was pushing back against the scene because of one small detail that didn’t sit well with him shows how much a perfectionist he was at that time. He got lazier as he got older because he didn’t feel like it mattered.

I’ve always wondered what Brando’s career would have been like if he wasn’t an instant star so young. If he had struggled more and really had to find an outlet for his talents that he was more satisfied with, I think he would have had not just a longer lasting career but also would have made better work.