Essentially, within the statement, René Descartes is saying the essence of our being is within our thoughts. However, what if the thinker (the elusive "I") is not ACTUALLY us? What if we are actually the OBSERVER of our thoughts, and not the one who produces them? If we identify ourselves as purely the voice in our head, we lose sight of our actual being--the soul who is beyond our physical prism.
Perhaps our conscious awareness as an observer more captures our core. We are conscious beings. We can dissociate from the thinker and become aware of our thoughts. We can see ourselves from a third-person perspective, and detach from the constant stream of consciousness, which is a narrative of our world. We are constantly thinking, observing, judging our world. If we heavily identify with our thoughts and emotions, we lose sight of a bigger picture. We are the observer and experiencer. We should recognize our thoughts are not actually us. They are a product of our biased, subjective experience in life. We do not actually see the world as it is. We add meaning to the world through our lens, which is fogged by our past associations and learned thoughts. We cannot label ourselves as simply thought because we are much more than this.