Katy Perry has become a hoarder with an obsessive compulsive disorder thanks to her modest childhood.
The Roar hitmaker, who has been diagnosed with OCD, insists she is a "hoarder by nature", because she had no money to collect things when she was a child.
"You get something and you're like, 'I'm never going to get it again', or 'I'll never have the means to get it again'," she tells Paper magazine. "It's this psychology behind it, when all of a sudden you can just purchase something - it's very wild for your brain."
"I'm very OCD and I don't say that lightly," she says. "It was just a product of me trying to control my environment."
However, Katy has no issues with de-cluttering, revealing her occasional clean-outs have spilled over on to her boyfriend Orlando Bloom's things.
"My boyfriend doesn't even know that I threw away his toiletry bag while he's been gone," she says. "I told him, 'I got him a new one for Christmas'. He said, 'Oh, this has been around the world for 10 years', and he wanted to keep it in a drawer. I was like, 'The moment you leave is the moment this thing is going in the trash'."
But there are some precious items Katy will never get rid of - her costumes.
"I have all of them," she adds. "I have my costumes, my dancers' costumes, all of my tour sets. My whipped-cream gun. I'm a collector, as I like to call it. I don't have cars in my garage, I just have a garage full of clothes. That's how it's always been for all the different houses I've lived in."