You may not have thought about breathing even once today. You have, however been breathing. Well, duh!
The act of breathing has unique life sustaining power. When we become aware of breathing, we experience the foundation of most meditative exercises.
This is not just the physical process of moving air into and out of our lungs. That physical breath is truly the vehicle that the life-force (spirit) employs to manifest in the physical world.
When we took life, the first thing that we accomplished was inspiration, we literally breathed air into our lungs. That was followed soon thereafter by expiration...we breathed out. Thereafter, we respire. Note that these words are rooted in the Latin word spiritus (spirit). To inspire is to breathe in the spirit. To expire is to breathe the spirit out. When we leave this life, the last thing that we do is to breathe out, hence, to expire (spirit leaves).
The Hindus call this force Prana, the Chinese Taoists, Chi, Hebrews, the Breath of Life, Christians, Holy Spirit.
In order to avoid the requirement that we believe something, we are referring to spirit here as un-manifested (spiritual) energy. It could be called Pure Awareness, the essential nature of who we are.
Because our breath is intimately connected to the spiritual life-force, it controls all aspects of the mental, physical and spiritual processes in our human life. Our breath controls experiences of pain and fear. It contains powerful healing energies.
When you close your eyes and notice that you are breathing, consider that this has been going on all day, perhaps without your having to assist it or to even be aware of it. Now that you are aware, notice one breath. By the way, that's all you are able to notice...this one breath. Notice the tempo of your breathing.
Notice, if you can that while you are aware of this breathing, the pace of your "thinking" has significantly decreased. When you notice this, your thinking will then probably "jump back" into your consciousness. Just relax and focus again on your breathing. Notice, if you will that you achieve even more relaxation and relief from random mind chatter.
If this seems to be some sort of meditative practice, that's because it is. For a few moments here, we have been meditating. Just close your eyes again. Breathe.
Be aware, each day of at least one breath. That way, you meditate every day.