The ability to just not care is almost like a superpower. It sends a message of immovability and confidence, probably in self, but the confidence could be placed in something else—like God. Not caring sends this message for good reason.
Most of us walk around with an inner turmoil—a storm rages within each of us, full of fear, worry, and doubt of someone or something or self. That storm makes us hypersensitive to the normal world around us. So, it is not really life or circumstance we don’t need to mind. The thing we needn’t mind is within.