(Cover) - EN Showbiz - Zach Galifianakis thinks The Hangover is so successful because people enjoy watching the suffering of others.

The 41-year-old actor gained high praise for his role playing oddball Alan in 2009 comedy smash

The Hangover, and he has reprised the role for The Hangover Part II which he is currently promoting.

Zach has been pondering what makes The Hangover movies so successful, and he thinks it could be down to the way moviegoers enjoy watching the film's disaster-prone characters get into scrapes. He also laughed that many cinema fans can relate to the over-consumption of alcohol.

"I think a lot of people have been hungover and they might have some dark patches of the night before so I think that's relatable. And I think that people like to watch people suffer," he laughed in an interview with the BBC.

Zach's co-stars include Bradley Cooper and Ed Helms, and the latter admits making the movie was enjoyable but extremely challenging. The star was initially shocked when he read the script for The Hangover Part II, as he hadn't thought the plot could get any wackier than the first movie.

"Just reading the script was like, Wow'," he laughed. "Bangkok is a beautiful magical place but it's also incredibly tense and overwhelming and to be living there for nine weeks shooting on a crazy schedule - it took a lot out of us." (C) Cover Media