Mindsight is a specific, trainable skill for perceiving your own mental processes

Siegel defines mindsight as the capacity to perceive and name one's own internal mental states — thoughts, emotions, sensations, impulses — with enough clarity and distance to observe them rather than being completely absorbed inside them, and to do the same for other people's minds through empathic insight.

He's explicit that this is not a fixed personality trait some people simply have and others lack, but a learnable skill akin to physical fitness, one that improves measurably with deliberate practice, particularly through certain attention-focusing exercises he draws from contemplative and clinical traditions.

The skill matters clinically because many psychological difficulties, in his account, stem less from the content of a person's thoughts and feelings than from being unable to step back and observe those states with any perspective, becoming instead completely fused with whatever mental state currently dominates.

Takeaway: the ability to observe your own mental state from a slight distance is a specific, trainable skill, not a fixed trait you either have or lack.