James Corden Says British People Think He Was Fired from Late Night Job

James Corden walked away from his "Late Late Show" hosting gig on his own terms ... but people in his native UK just can't quite believe he wasn't fired, at least according to him.

The Brit explained on "Jimmy Kimmel Live!" Tuesday that despite him assuring people he and his wife Julia moved back across the pond so their 3 kids could be closer to their grandparents, people are convinced he's lying ... and think CBS canned him.

James says he's had his fair share of pub convos about his talk show departure ... and no matter how many times he tries to set the record straight, he says, "People will honestly be like, 'You don't have to give me that bull***. It's fine, mate. If you got fired, you got fired!'"

Kimmel even suggested JC get a letter from CBS proving he wasn't fired ... but the "Carpool Karaoke" star said it wouldn't quite do the trick ... 'cause no one back in England even knows about the American network.

Nonetheless, JC says it's a whole new world after wrapping the long-term hosting gig ... 'cause he didn't realize how "institutionalized" he'd become while working on TV. He says ending every day with a standing ovation had become quite the routine for him.