I like that this sutra starts us off on one of the most important aspects of Dhyana and meditation practice. The "now" part. The part about being present. Not thinking about what happened 2 minutes ago or what you will be doing later. Not thinking about how you felt a minute ago, but allowing all of those thoughts to pass by and being in the now. And this is when the process of Yoga begins. I like the idea of the yoga practice as a process. Its not about the end result -there is so much in the process. Every present moment there is something to be learned, and then moving on from that moment into the next present moment. This is why I always think of Yoga as a journey. You have to let go of the idea or desire of the end result - relaxation, being able to touch your toes, come into a headstand, etc. By doing the work you will eventually get there, but you have to surrender to this and trust it. If your mind is set on the goal only, you lose the intensity of the work and make it more difficult to reach your goal.
It is these desires and thoughts about the past or the future, that creates the ripples in our sea of consciousness. It distorts our journey and makes it more difficult to see what is really there. When you get into a stressful situation, you can feel your perception distort, we become defensive, angry, upset. But staying present helps us to see the reality and work through difficult times. Dhyana is being able to hold ourselves in the present place despite the challenges we meet in life day to day. It helps us through those times and brings us to a more calm state where we can see more clearly.