This phrase is often said to someone right before you do something that is either going to:
A) Cause them injury
B) Cause them intense embarrassment
Example situations when "Think Fast!" can be used:
* Throwing another person a basketball
* Throwing another person juggling kittens
* Throwing another person a lawn dart.

See also: Heads up

Y'know, if you log in, you can write something here, or contact authors directly on the site. Create a New User if you don't already have an account.