There's the story of the girl in the marching band. At one July 4th parade as her marching band arrived in front of the large crowd gathered on Main St, the girl spotted her mother in the crowd. The proud girl then yelled to her mother, "Look Mom, I'm the only one in step!"
Many of us have those moments in our life where we feel like we're the only ones in step. We all temporarily lose our identity from time to time or should I say the person we best identify with as "I."
There are some that identify themselves as the physical body (our lower nature.) Others identify themselves on a psychological level. Others believe they are the personality that others see on the exterior or our emotional self.
What we truly are, is the SELF that endures throughout all the changes of the body, personality, psychological and emotional fluctuations. These components are the tools we use during this period of what I like to call "God School." Our Spirit, our Higher Consciousness is what we will take away from this experience, on this plane.
Anything not Divine will die off or shed, leaving the eternal (infinite.) Motion will eventually stop. That applies to everything from the smallest molecular particle on earth, to the fusion on the face of the Sun, or any physical matter in the cosmos for that matter.
The Hindu word Atma is defined as consciousness without object. It's our consciousness without the distractions of our environment, thoughts, feelings, people, emotions etc... This is the point at which everything on this plane is blocked out and all your left with your pure, Divine Higher Self.
You might say that you've never experienced anything like that in your life, right? Have you ever woke-up from a deep sleep and forgot, for a split second, where your are or who you are? That's Atma, without any baggage what-so-ever.
Yoga and different meditation exercises are a pathway to the blocking out of all the distractions that keep us from finding our Higher Self. Add this Higher Self with the Nirvana (a condition of great bliss) and you have our next plane of purifying.