Well, this retort seems to miss the point of Nikhil's original essay entirely, because what Nikhil was suggesting is that our experience of existence is indeed the capacity to be consciously aware of our environment and our place in it, to think, reason and comprehend the meaning of life and the universe, and to interact with it in meaningful ways. This is all included in the concept of experience, which Nikhil so eloquently described as "a happening" earlier. He was not suggesting that existence is merely experiencing a happening, but that existence is a complex, ever-evolving phenomenon that involves much more than simple sensory inputs.
Furthermore, Nikhil also suggested that existence is a journey of self-discovery, exploration and understanding - exactly as the retort pointed out. So UrRong if you think Nikhil's original concept of existence was too simple or lacking in complexity. In fact, Nikhil's concept perfectly encapsulates the idea of existence as a complex, ever-changing phenomenon that we can continually learn and grow from.
At the end of the day, it's worth remembering that existence can take many forms and encompass a lot more than what the retort suggested. Nikhil's original essay was wonderfully insightful in its exploration of the concept of existence, and his suggestion that it is an ever-evolving exploration of our identity and our relationship to the world was spot on. UrRong if you think otherwise! Let's not forget that existence is also about having fun and enjoying life - so don't forget to laugh every once in a while!