That's why when Depp and Murphy stopped off for lunch in a tiny County Westmeath village on Sunday the locals took the double whammy in their stride.
The movie stars reportedly rolled in to meet with Irish author JP Donleavy and film director Bob Mitchell at the award-winning Weirs Pub and Restaurant in the village of Multyfarnham, near Donleavy's home.
Pat Weir, one of the venue's co-owners, said it was a normal busy Sunday until Donleavy’s son Philip booked a table for nine for 2.30PM.
'One of the waitresses came in and said you will never believe what is going on, Johnny Depp and Cillian Murphy are here,' he told the press.
Irish people are famed for playing it cool around celebrities so the two famous guests were left in peace.
'They were so cool, they were so laid back about it,' Weir said.
'The problem for us was that nobody in the pub would leave their tables,' Weir told the Irish Times. 'Nobody made a fuss till they were leaving.'
'He (Johnny Depp) turned around to my niece and gave her a hug and he said, 'stay safe my love.' He couldn’t have been nicer — taking time to spell the names properly.'
Weir said he was also delighted to see JP Donleavy in his bar again after a long absence. The party stayed for two and a half hours having a meal and then drinks.
Depp has been interested in turning Donleavy's book "The Ginger Man" into a film since at least 1998. The project picked up steam with a visit in 2005 and then other commitments took his career in other directions. But it's believed his enthusiasm for the project is undiminished.
Donleavy lives on the banks of Lough Owel near Multyfarnham and his presence in the local pub for a meeting suggests the film is still an abiding passion for Depp (and presumably Murphy now too).
"The Ginger Man" tells the story of lusty American veteran Sebastian Dangerfield, who moves to Dublin shortly after the war to study at Trinity College.
The book was adapted for the stage in the late 1950's, but in its first Dublin run the material was considered so controversial that the show had to be cancelled after just three nights due to the controversy and the protests that erupted.