Rule reminder
Similar idioms differ in: (1) intensity ('andare su tutte le furie' > 'perdere le staffe'), (2) direction (you do for others: 'togliere le castagne'; others do to you: 'essere alle strette'), (3) timeframe ('rimandare alle calende greche' = forever; 'fare le cose a metà' = incomplete now), (4) social focus ('fare bella figura' = public impression; 'essere al settimo cielo' = private emotion).
After winning the championship, the young athlete became insufferable — constantly talking about himself, never listening to others, dismissing teammates' contributions. Which idiom best describes this change?