50-year-old Depp playing a 25-year-old Thompson?

Johnny Depp has definitely aged as well as anybody I've seen, but he played Hunter Thompson circa 1970 about ten or so years ago, and here he's playing Thompson circa 1960, but HE is now ten years older. It seems a little strange for a guy as old as Depp do be as naive as Thompson's character is here.

The romantic pairing with Amber Heard is interesting too since in real-life he could probably be her father, but I guess life imitated art there (and, hell, if you can look as good as Depp at 50 and still date gorgeous 25-year-old bisexuals like Amber, more power to you). Still, there's something surreal about the age gap between Depp and his character here. . .