Peace of mind...

There is no such thing as peace of mind. Mind means disturbance; restlessness itself is mind.

A level of maturity is reached when nothing external is of any value, and the heart is ready to relinquish all. Then the real has a chance and it grasps it. Delays, if any, are caused by the mind being unwilling to see or discard.

You cannot see the true unless you are at peace. A quiet mind is essential for right perception, which again is required for self-realization.

Nisargadatta Maharaj from I Am That