He/She is about as crazy as a Betsy Bug.
If someone says this you are truly crazy but um....what is a Betsy Bug and how crazy does it get?
Don't give anyone a hammer to beat you over the head with.
TRANSLATION: Don't tell people all of your business. It gives others the upper hand to make you a part of gossip. One day it will come back on you and you might regret it thus beating you over the head.