George Clooney wasn't a fan of Christmas morning as a kid, because his father insisted he and his sister Ada visit less fortunate families and hand out gifts before they could open their own.

The actor's dad, retired newsman and entertainer Nick Clooney, was a local celebrity in Ohio and would help out fans who had fallen upon tough times over the holidays, buying their kids gifts and playing Santa Claus every 25 December.

George now admires what his dad did and appreciates the fact he was part of his Christmas Day generosity, but he hated having to make trips to the poor parts of the state before his own fun could begin at home.

During an appearance on David Letterman's Netflix show My Next Guest Needs No Introduction, the Ocean's Eleven star says, "My father and mother were really good people and they pay attention to the community, but it's not fun being the child of people who do really good things...

"My father would get letters from people who'd have bad years because he was famous... so every year my dad would collect these letters and he'd pick one and we'd have to go shopping and buy presents for the kids of this family... and Christmas morning, before we could open any presents or anything... we'd drive for like an hour to some stranger's home and I remember going in and cleaning their kitchen for like an hour and a half, just my sister and I, and then brought their kids presents."

Clooney hated playing Santa Claus to strangers' kids every Christmas, adding, "It, at the time, seems sort of awful because you're thinking, 'I'd like to, one Christmas, come downstairs and see what Santa brought'."

But he admits his father's generous acts helped shape him into the man he has become: "It informs how you are going to continue on," he tells Letterman.

The actor's close friend and business partner Rande Gerber recently revealed in 2013 George handed each of his 14 best friends $1 million as a thank you for helping him out when he was a struggling actor. Clooney also quietly makes several donations to several worthwhile causes and is considered one of the most generous people in Hollywood.