Justin Timberlake -- Good Genes or Good Docs?

Justin Timberlake's good looks are full-time!

Here's a 18-year-old version of the 'NSYNC standout rocking curly locks back in 1999 (left) and 19 years later ... the Super Bowl LII halftime hunk -- who just celebrated his 37th birthday -- doing a Press Conference in Minneapolis earlier this week (right).

Man of the Woods.

The question is ...