Lets see some examples...
"I could care less." ~> means that you don't care BUT if you "care less" then at least you care some!
"Like chalk and cheese"~> means not alike but you can't substitute a chalk for a cheese right?
"To overlook" ~> means to miss something you should have noticed but if you are over-doing something, isn't that doing it too much?
"Don’t Cross A Bridge Until You Come To It" ~> means not to mess with anything unless something bad strikes
"Prevention Is Better Than Cure"~> means do something to prevent that bad event from happening
Do you know of any other expressions? I know that after so many years, I still struggle with "the alarm going off" in the morning so Ring along!