Then & Now Pics of the Guys You Loved In The Early '00s Will Make You Feel Really Old — PHOTOS

Not only is the “Suit & Tie” singer a bonafide superstar in the music biz, he’s also the funniest guest star on Saturday Night Live, starred in an Academy Award-nominated film, and is married to Jessica Biel. Things are good for JT.

The other boy band fan favorite from competing boy band the Backstreet Boys. Apparently blondes really do have more fun.

His career hasn’t skyrocketed in the years following the decline of the Backstreet Boys, but he has made some positive changes in his life following his earlier struggles with drug abuse, and he seems happier and better than ever.

The That ’70s Show star had us wishing we could romance Kelso IRL.

He has his own production company, a starring role on Two and a Half Men, and a baby on the way with his That ’70s Show co-star, Mila Kunis.

I really felt for Usher, even as he faux-confessed to impregnating his “chick on the side.” (What can I say, that was a really great album!)

Usher’s still got it. Voice, style, swag… basically everything about this guy has improved with age, so much so that I can forgive him for giving the world Justin Bieber.

Another Summerland youngin’, he also sang the perfect (not at all cheesy) love anthem “Beautiful Soul.”

You can tune into ABC Family’s sitcom Young & Hungry to see how he looks with glasses, if that’s your thing.

The Virgin Suicides and Pearl Harbor star was the face to have on your bedroom walls.

He’s baaack! Hartnett has returned to us with the spooky Showtime series Penny Dreadful .

He played Fez on That ’70s Show and dated basically every starlet under the sun.

He’s Demi Lovato’s beau. And they’re actually kind of sweet.

Pharrell wore an unfortunate amount of trucker hats during his N*E*R*D days.

It’s all about the Arby’s hats these days.

The Felicity star was one third of a love triangle back then.

Now that he’s on Scandal, not much has changed… except for the fact that he gets impossibly more handsome year after year.

The Van Wilder star wore track suits. In public.

Today, Reynolds has classed up his look — probably with help from his fashion icon wife, Blake Lively.

The Walk to Remember star made us sob uncontrollably… and still does whenever the movie comes on ABC Family.

The former Nikita star is now defending witches on the new WGN series Salem.

Sure, he was Dawson from the Creek, but I’ll always remember him as Sean Bateman from the dark college flick The Rules of Attraction.

JVDB was the best part of the two sadly canceled (and terribly titled) sitcoms Don’t Trust the B in Apartment 23 and Friends With Better Lives.

Remember when this guy kissed Lizzie McGuire and then proceeded to start a feud between Hilary Duff and Lindsay Lohan? GOOD TIMES.

Well, he has definitely grown up physically, but considering that he’s still pining for Duff, I’m not so sure he’s really out of the ’00s.

The Freaky Friday and A Cinderella Story star never really looked like a teenager, even when playing one for years on One Tree Hill.

The hair is SUCH an improvement.

Oh, hey, remember him? Of Swimfan, Clockstoppers, Bring It On, Romeo & Juliet… I could go on, because, essentially, if a teen movie was made between 1997 and 2004, he was in it.

He continues to look like a hybrid of Justin Theroux, Jason Biggs, and Freddie Prinze Jr. A+, Bradford.

The American Pie star really knew how to wear a leather jacket.

Klein has a recurring role on Wilfred and definitely has a Don Draper vibe.

This charming cutie got his start on Summerland before moving on to his role in the High School Musical trilogy.

One word: Damn.