The problem is in adding the word "just" for no reason. It makes the statement of a fact a type of rhetorical device. It is the difference between saying "I a

The problem is in adding the word "just" for no reason. It makes the statement of a fact a type of rhetorical device. It is the difference between saying "I am a biological entity" and "I am just a biological entity". There are all kinds of connotations that come along for the ride with the latter statement. Then there is the counter with the romantic statement that "I am not just a biological entity".