Fame and money were definitely major motivations for Ioan. He didn't enjoy his time at RADA and only got a lead role in his final year. In a 2002 interview, he talked about Titanic and how he wanted to be Leonardo.
Mad about the boyo | Film | The Guardian
'Even though it was miserable and took so much time, the pay-off is so incredible. I was only playing a very small part - I wanted to be Leonardo DiCaprio, you know, in my own blockbuster. That's the quest I'm on. It made me more hungry. I hope that everything is a means to that. I'm not embarrassed to admit that that is an ambition. And why not? Twenty million a shot? Yeah, thank you very much." He has no time for actors who say wealth and integrity don't mix. They are self-deceived, he thinks. "People say, 'Oooh, money, it doesn't make you happy.' But because I feel quite happy at the moment, money would be a nice little bonus. To people who say it'll make you miserable, I say 'bollocks'. As long as you understand that you find happiness in real terms through family, friends and love, then money is just a nice bonus.'
'I just knew I wanted to do this forever' - Independent.ie
'Looking back," says Gruffudd of his seven years on the soap, "I was an awful actor, but I just knew I wanted to do this forever and I was happy to learn it as a craft and go to Rada and do everything I could to improve myself. And, you know, even then I imagined myself as a movie star and saw myself sitting in a house in Hollywood and gallivanting with the stars. So when I'd trained and established myself, I realised the dream was still there and I put up my hands and admitted that I wanted to pursue it'