Here's a 48-year-old Hugh Jackman flashing a thumbs-up in a biker-inspired black jacket and a pair of upsetting sideburns over the weekend (left) ... and Henry Winkler posing as his iconic jukebox-punching "Happy Days" character, Arthur 'Fonzie' Fonzarelli, back in the '70s (right).

Both of these looks have jumped the shark.

We're just sayin'.