Sir Ian McKellen and Michael Sheen have recounted being mistaken for other actors or their characters.
Sir Ian, 84, who played the wizard Gandalf in The Lord Of The Rings trilogy and The Hobbit films, shared that he has previously been mistaken for the late Sir Michael Gambon – who played Albus Dumbledore in the Harry Potter films.
He told The Graham Norton Show: “Michael Gambon, who played the other wizard, and I were often mistaken for each other, and an odd thing happened last week.
“I was waiting for a train and two women in their 20s said, ‘Are you Michael Gambon?’. I told them that he was dead, and they said, ‘Yes we know but are you him?’ I think they thought they had seen a ghost.”
Sir Michael died aged 82 last year.
Welsh actor Sheen, 55, said: “A lot of people think I am Andy Serkis from Lord Of The Rings.
“I was once followed out of a restaurant in LA by someone screaming Gollum! Gollum! Gollum! I am not recognised as Andy, but just the hideous character he plays. It’s terrible.”
The Good Omens star also spoke about directing three-part BBC drama series The Way, which will be available on BBC iPlayer from 6am on February 19, and also airs weekly on BBC One at 9pm from the same day onwards.
Written by James Graham, whose credits include the TV adaptation of Quiz, and filmed in and around Port Talbot, the series imagines a family caught up in a civil uprising which begins in their small industrial town.
Sheen told Norton: “I loved it. Some people say the hardest thing about directing is being asked so many questions all the time, but that’s the bit I like.
“I am a control freak and I want it to be my decision. I really enjoyed it.”
He added: “The difficulty of filming in my hometown (Port Talbot) was that while I was in the middle of directing so many people I know were coming up for a chat or asking me to fix things in the town like the state of the bins.”
Other guests on Norton’s BBC show include One Day actress Ambika Mod, comedian Josh Widdicombe and singer Gabrielle, who performs her single A Place in Your Heart.
The Graham Norton Show airs on BBC One at 10.40pm and is also available on BBC iPlayer.