in your right mind
in (one's) right mind
Thinking soundly; rational. Usually used to set up a context in which any sane person would or could do, say, or think a certain thing. No one in their right mind agrees to those kind of terms—unless they sign a contract without reading it. You must not be in your right mind if you think that breaking up their wedding is a good idea.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
(not) in your right ˈmind(not) mentally normal: Nobody in their right mind would buy a used car without driving it first.
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