Mental Indifference and Lack of curiousity

Sweet Mother,

Are mental indifference and lack of curiosity a sort of mental inertia?

Usually they are due to mental inertia, unless one has obtained this calm and indifference through a very intense sadhana resulting in a perfect equality for which good and bad, pleasant and unpleasant no longer exist. But in that case, mental activity is replaced by an intuitive activity of a much higher kind.

Ref : Some Answers from The Mother