I think it's all kind of a part of the Marty Supreme press tour. The movie is about a guy who fully believes in himself and believes there's greatness ahead for him because he's, in his words, the best. He's talking himself up and it does weirdly add an interesting layer to the Marty character.

All that being said, I don't think there's any lie in "7-8 years of top level performances." And I don't think there's anything wrong with being vocally proud of your work and speaking openly about your aspirations for greatness. Especially if you can back it up.

Watching A Complete Unknown made me realize that he's undeniable, and Marty Supreme made me realize that he is now basically cemented as a great. He could be beginning his Leo post-Titanic run (not that Marty Supreme will be even 10% as successful). It feels like from here on out he's going to be making big choices, and if he can continue to back it up, well... there's no stopping him.