Just think, the Las Vegas hijinks in 2009's The Hangover (a.k.a. the highest grossing R-rated comedy of all time) might never have occurred were it not for the missing-in-action character of Doug, played by Justin Bartha. After taking off for Sin City with his crew in hopes of celebrating a bachelor party they'd never forget, the groom-to-be's big outing instead evolved into a night that everyone forgot, resulting in one of comedy's most memorable mornings-after.

This weekend, the entire cast is back and more fucked-up than ever in The Hangover Part II, in which Bartha's character sobers up much better than his ill-fated co-stars (Bradley Cooper, Ed Helms, and Zach Galifianakis). To help you get a better handle on your own post-drunken-night blues, we consulted Bartha for words of wisdom on how to survive your next epic hangover.

Complex: Was it easier or more difficult than some might think to portray a bombed groom in The Hangover? Did the role require a fair amount of "research"?

Justin Bartha: It's not that difficult to play wasted when you've spent your entire life preparing for this one role. My friends and family are appalled at my dedication to making my performance in the Hangover movies so authentic. They keep telling me, "But Justin, you play the responsible one of the Wolfpack. You don't need to ‘prepare’ so much." They aren't artists like I am. They just don't understand.

Can you recall the worst hangover you've ever had? And, having survived it, what are some red flags that might hint to readers it's a good time to cut the drinking short? 

Justin Bartha: The worst hangover I've ever had was probably when I was a kid and tried drinking for the first time. I woke up next to my gym teacher...in school. Good thing it was a Saturday and he could give me a ride home.

That said, you can always tell it's a good time to stop drinking when the alcohol becomes way too easy to drink. When you can do a shot and you don't even wince a little bit, it might be time to order a cup of coffee.

What's a typical afternoon in recovery like for you?

Justin Bartha: When I am really Hungover—I only capitalize this word now—after a long night, I like to curl up and watch any movie that has a character that curls up and watches movies after a long night.

Do you have any go-to, surefire hangover helpers? 

Justin Bartha: My go-to, surefire hangover helper is a nice big portion of Hamburger Helper. This is very easy to prepare; you simply brown the meat, and then drain the fat. Then mix the ingredients that come with the package—seasoning, noodles or rice, milk and/or water—and let it simmer. This meal can easily feed a hungover family of four for under 15 bucks! That's hard to beat.

Lastly, what's the most important thing to keep in mind when nursing a hangover? 

Justin Bartha: Breast milk is not actually a good hangover remedy. It is, however, a delicious mixer for a vodka drink.