Mindfulness is a misnomer.
It means to get out of your head by leaving your thoughts and gaining a greater awareness of the physical world in front of you. in other words, "to live in the moment".

Roll your eyes if you wish, but Deepak Chopra was right, "the mind is a spoiled child", constantly demanding attention. There is a difference between "the thinker having the thoughts" and the thoughts themselves. I dare you to try to go 30 seconds with no thoughts or images in your mind. You'll see just how spoiled it is.

Another practice common to mindfulness is to learn to truly listen instead of listening for a chance to interject your thoughts, opinions and experiences. It's another way to get out of your head and actually connect with the person you're conversing with. It is seldom reciprocated but has it's benefits.

The main theme of mindfulness is to learn not to worry about things which usually never come to pass. The future is fluid. All of the philosophy is intended to allow you to find peace in a complex and constantly changing world.