You're not the only one with a weird habit. Even celebrities do weird things when no one is looking. Here's a list of what these 19 celebrities do. Check it out below. Weird? Or WTF? Or just...normal?

Britney can't stop chewing her nails.

Beckham has to have everything in pairs in the fridge.

Eminem can only sleep well in pitch black bedrooms.

Catherine Zeta Jones only uses strawberry toothpaste.

Bill Gates can't go to sleep without reading in bed for a while.

Arianna Huffington banned all electronic devices from her bedroom after her burnout.

Steve Jobs used to eat so many carrots that his skin turned slightly orange for a while.

Barrack Obama believes all good things can happen after 2AM.

Cameron Diaz mostly opens doors with her elbows instead of her hands.

Jennifer Aniston can feel safe if she enters a plane with her right foot first.

Demi Moore is crazy about bloodsucking leeches, used to detox her body.

Katy Perry brushes her teeth six times a day.

Jessica Simpson is addicted to nicotine chewing gum.

Mariah Carey only eats purple foods such as egg plants or grapes three days a week.

Megan Fox listens to Britney Spears on plane flights or else she'll feel unsafe.

Paris Hilton believes in 'knocking on wood.'

Simon Cowell performs serious tree climbing each and every day.

Pamela Anderson is anxious looking in mirrors.

Johnny Depp plays with his Barbies if he gets bored.