Johnny Knoxville realised he was terrible at smoking weed when he hung out with Willie Nelson

Johnny Knoxville realised something really important when he was smoking weed with Willie Nelson, that he is absolutely terrible at smoking weed.

Nelson might be the only person in the world more associated with marijuana than Snoop Dogg and a number of famous figures have hung out with him.

Among those is Jackass star Johnny Knoxville, who came to the realisation that he was actually a pretty terrible toker, though to be fair to him he was playing in the big leagues.

Appearing on The Howard Stern Show the star explained that he was smoking with Nelson when he reached the epiphany that he was actually really, really bad at this.

Paramount Pictures

It's fair to accept that maybe you're just not cut out to do some things, and while Knoxville has put himself through all sorts of punishing trials it seems as though hanging out with Willie Nelson is one ordeal he can't hack.

"Yeah, I'm not very good at smoking weed. It hits me all wrong. He doesn't ask, he just sits down and joints start going around. I only took two." Knoxville told Howard Stern.

When Stern asked him how he'd cope with 10 hits Knoxville was certain that 'I would pass out', while Stern suggested he might be 'dead'.

"There's been a few times people just smoking going 'boop'," Knoxville continued, steadily toppling his arm over to mime people falling down as he discussed a documentary being filmed by a Jackass co-star.

The cameramen were filming on his bus, the joints were going around, the cameraman took a hit, a few hits and all of a sudden the cameraman goes face first onto the floor with the camera."

It's not the only time the Jackass frontman has spoken about his seeming inability to get blazed, telling The Late Late Show With James Corden that he thinks he might be 'allergic' to weed.

Jackass Forever/Paramount Pictures

Joking that if you hung out with Nelson you 'won't remember too much' about it afterwards, Knoxvill went on to say that weed just didn't seem to be the thing for him.

He said: "I love the idea of smoking weed, I love the smell of it but I think I'm allergic to it because I get crazy dizzy.

"Willie's weed is so, when he offers it to you there's no way to say no to Willie, I'm like 'I gotta look cool when I take it' and I try to ghost-toke it and put it in front of my lips but not actually, but it never works."

"It always gets in there."