You can shut your door on a thief but there is nothing you can do about a liar.

This is something said to me growing up to remind me that you must be mindful about what is being said to you and the credibility of who is saying it.  While you cannot do anything about a liar, you can think for yourself and determine if something you hear is credible.  If you fall for it, don’t worry, you won’t fall for it a second time.