Caleb Followill often worries he's not the right person to be Kings of Leon's frontman.
The singer performs in the rock band with his brothers Nathan and Jared and their cousin Matthew.
The men are renowned for having a fraught relationship. Last year Caleb walked off stage during a show after claiming he felt ill, much to his bandmates' irritation. Jared later took to Twitter to tell fans there is an "internal sickness" within the group which needs to be worked on.
Caleb admits he often struggles with his work as he doesn't feel ready to be in such a famous group.
"I'm not going to hide it. I want us to be the biggest f**king think in rock ever. I want kids singing our songs 50 years from now. But sometimes I wake up and feel like I'm not the guy to be fronting something this big at all," he told Q magazine.
Part of the problem is that Caleb can't get used to his celebrity status. The Followill brothers were raised in the southern states of America and moved around as their father was a preacher.
Becoming one of the best-known people in the world still doesn't sit well with Caleb.
"I can be at a party full of famous faces and I'm more relaxed now. But then, like I went out to this local restaurant and Hugh Jackman pulled up outside on a bicycle," he recalled. "I was sitting there thinking, You're Wolverine man! Wolverine doesn't tie a bike to a lamp post!'"
The star also has his doubts about some aspects of the band's career.
Their 2009 single Sex on Fire remains one of their most popular songs, but Caleb is tired of it.
He claims the song started as a joke and he never thought it would make it to an album.
The 29-year-old also has reservations about the promo for the group's song Radioactive. It was supposed to be in honour of the group's time in Tennessee, and saw them enjoying country life with a group of African American children alongside them.
"Did you see the Russell Brand film Get Him to the Greek? The pop star in that film makes a very lame Live Aid-style charity video called African Child. When I first saw our video I thought, We have made the video to African Child,'" he lamented.