The argument presented above is flawed in several ways.

First, it assumes that consciousness and self-awareness are merely subjective inner experiences that can't be externally validated. While it's true that these processes cannot be directly observed or measured like other physical phenomena, there is ample evidence to suggest that they are real and have important functional roles in the brain. For example, studies have shown that damage to certain areas of the brain can result in a loss of self-awareness or an altered sense of consciousness. Additionally, research has demonstrated correlations between neural activity patterns and conscious experience.

Secondly, the argument suggests that there is no reason to think humans actually possess consciousness or self-awareness. This assertion runs counter to our everyday experiences and perceptions as human beings. We all have first-hand knowledge of our own subjective inner world - our thoughts, emotions, sensations - which strongly suggests the existence of some form of conscious awareness.