If you're in the UK - look up. There's a large ring around the Moon tonight. This is a fairly common phenomenon and you can read about what causes it here:

http://www.universetoday.com/20402/ring-around-the-moon/

Idioms and expressions - "To be full of yourself"

“Be full of yourself” - Think you are the best thing ever! 

Examples:

“Ugh, I hate Paris Hilton, she’s so full of herself”