Sean Penn is known to be pretty laid back in interviews, but he took things to a whole new level during an appearance on Monday’s “Late Show with Stephen Colbert”.

The 57-year-old sparked an online frenzy as he smoked two cigarettes during the chat and told the talk show host he was a little worse for wear after flying all night.

Admitting he’d taken a sedative before, Penn, who released his new book “Bob Honey Who Just Do Stuff: A Novel” Tuesday, explained: “I’m doing well. You’ve inherited a little of the Ambien I had to take to get to sleep after a red-eye last night.”

“So, in other words, you’re still a little bit on the Ambien train right now?” Colbert then asked, to which Penn replied: “A little bit,” before lighting a cigarette.

The interview prompted Sara Gilbert, who was joining Colbert next, to give her summation: “Wow, I just want to say, Sean Penn makes me look energetic.”

Unsurprisingly, Penn’s dazed appearance got numerous people talking on Twitter. See some of the responses below:

RELATED: Sean Penn Opens Up About Relationship With Ex-Wife Robin Wright: ‘We Don’t NOT Get Along’

Monday’s interview also saw Penn speak out about why he was thinking about taking a step back from acting.

After Colbert, who asked Penn to “stop smoking” for the sake of his health, insisted he’d be “breaking hearts” everywhere, the two-time Oscar winner joked, “The ‘breaking hearts,’ plenty of people would be thrilled!”

He then added he finds it hard to “play well with others,” so had moved on to writing novels.

RELATED: Sean Penn Says He’s ‘Not In Love’ With Acting Anymore

In a complete change of topic, Penn then spoke about March For Our Lives, with him praising the students of Marjory Stoneman Douglas High School for leading the Washington, D.C., protest on Saturday.

The star explained of the horrific February 14 shooting, “Within days of that not only are they stating their case with incredible sobriety and articulate words but in such an inclusionary way. You feel like there are reasonable people who have been on the other side of this conversation who will listen to these kids.”

Catch “The Late Show with Stephen Colbert” weeknights at 11:35 p.m. ET/PT on Global (you can also watch full episodes online).