Mindfulness, as I understand, is attained through a focus on the breath and being able to let go of the inner dialog that we maintain.

One analogy depicts mindfulness as floating in a river. The thoughts pass by, like flotsam. It’s up to you whether you take them in hand and examine them for a few moments and then push them off to float away.

Although this can be done practically anywhere, the principal method for attaining the ability to realize it is sitting meditation. The transformative experience for the mind comes from focusing on the seated posture.

When first starting or being instructed, sitting cross legged or in half lotus requires such intense focus on the posture - and at times the difficulty of sitting still for even 20 minutes trying to focus on the breath - the mind eventually lets go of its attachments to thoughts and with practice, finds room for a deeper understanding of the self.