Scarlett would prefer to remain a mystery

Johansson said she would like to trade lives with President Bush. Picture / Reuters

Scarlett Johansson shows off in cleavage-baring dresses on the red carpet but in real life she would rather remain a mystery.

"I can't stand those articles where people spill their life story," said the actress.

"After a while I feel like I know more about them than their best friend does - and that's weird. It's better when you don't know everything."

Asked who she would like to trade lives with, she nominated President George W. Bush. "I could probably get some things done in the Oval Office."