Sutra 1.2: Yogas Citta Vrtti Nirodhah. Yoga is to quiet the chatter of the mind.
You'll probably see varying translations (but with similar meanings) of this sutra (i.e a terse phrase), one of 196 sutras composed by Patanjali sometime around the 2nd century BCE. These comprise the basic outline for what yoga is. Yes, yoga includes the asanas ("seat/posture", or the poses with which most of us associate yoga). Yes, they are an important part. But to give you an idea of their "place" in yoga, asanas are only mentioned twice in the entire 196 sutras.
So if yoga isn't "complete" just by doing those things we do on the mat in class, what in the world is it? What is the stuff in class for? Why practice the postures, or learn anything else beyond them?
A few Google searches will turn up a wealth of information. The Yamas and Niyamas are worth exploring. (These are basically "do's" and "don'ts", but don't let that turn you off. They are more of suggestions, saying if you do A, B will happen. If you choose not to, B probably won't happen. If you are truly satisfied with what you have, you won't long for more. And so on.) But there is so much to yoga that I couldn't begin to explain even what I know...this is a tradition thousands of years old.
As with everything else, I am interested in how yoga infuses with our lives. What good is having an awesome downward dog pose if you still find yourself wanting to punch the person in line in front of you for taking too long (or worse yet, doing it)? If the mind is going yappity yap yap throughout the day and you can't find that elusive sense of well-being, what good is knowing how to get in mountain?
The postures teach us how to find balance with our bodies. It is a starting point. If we can learn how the breath helps move into and out of poses, how we can be steady and alert (sthira) and comfortable and light (sukha) in exactly the same position - we can carry this throughout our day. Use the breath to take you to places of calm when you'd otherwise freak out. Practice being alert yet comfortable when dealing with other people.
Which brings me back to sutra 1.2. Yoga is to quiet the chatter of the mind. Ultimately, the poses, the meditation, the yamas and niyamas, the cyclical infusion of the yogic ideals into life creates a blissful hush in the mind. For most, it doesn't last. But with more and more practice, the periods of chatter-free time grow longer and closer together.
Whatever you may be facing in life, I PROMISE it is easier (and more enjoyable) when the mind is chatter-free (or at least the volume is turned down). The stuff you don't need seems to fade into the background (still there to be dealt with, but easily so) and the stuff you need? Front and center.
Take a breath, a deep, pure one, and exhale (from the abdomen) what you don't need. Allow your next inhale to bring with it a beautiful sense of lightness, full of whatever you need right here, right now. Keep breathing. Keep being. Enjoy.