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.
See also: mind, right
Farlex Dictionary of Idioms.

(not) in your right ˈmind

(not) mentally normal: Nobody in their right mind would buy a used car without driving it first.
See also: mind, right
Farlex Partner Idioms Dictionary
See also:
  • in (one's) right mind
  • in one's right mind
  • in right mind
  • anyone in their right mind
  • play with a full deck
  • there is (a) method in (one's) madness
  • have (a) method in (one's) madness
  • have (a) method to (one's) madness
  • method in one's madness
  • (a) method to (one's) madness