If I were to parse that quote, to me it means that yoga is a journey of the self (the traveler), through the self (the vehicle), to the self (the destination). So, I myself is the who, the how, and the where in the journey.
In Sanskrit, the word “Yoga” means to add or unite: uniting the body with the most powerful apparatus in a human being: the mind. It also means to reach a place which was previously unattainable, or a movement from a point to another, higher than the previous.
Hence, I am the traveler, the whole person (with both mind and body) who is undertaking this journey of self-improvement and uniting myself with my own true self. Yoga’s first 2 limbs, yamas, and niyamas, provide the ethical guidelines to help my mind and its thoughts the direction towards self-awareness. The Asanas and pranayama provide me means to keep my physical body healthy, without which I cannot undertake this journey. All along, I use myself as the vehicle in this journey.
Where am I headed? What is the destination? I am myself the destination. The Divine resides in me. I am seeking that connection with myself: my higher self, my peaceful self, my real self, my utmost best self that can be. Through the practice of yoga, I can peel the layers of myself and recognize my true self.
Some other useful quotes on yoga and the self that go along the line with this quote are:
Yoga is the perfect opportunity to be curious about you. – Jason Crandell
Yoga is not about self-improvement or making ourselves better. It is a process of deconstructing all the barriers we may have erected that prevent us from having an authentic connection with ourselves and the world. – Donna Fahri