Jon Kabat Zinn quotes:

By repeatedly bringing your attention back to the breath each time it wanders off, concentration builds and deepens, much as muscles develop by repetitively lifting weights."

In Asian languages, the word for 'mind' and the word for 'heart' are same. So if you're not hearing mindfulness in some deep way as heartfulness, you're not really understanding it. Compassion and kindness towards oneself are intrinsically woven into it. You could think of mindfulness as wise and affectionate attention.

When you see and feel the sensations you are experiencing as sensations, pure and simple, you may see that these thoughts about the sensation are useless to you at that moment and that they can actually make things worse than they need be.