You missed the point of the exercise. Of course it's extremely difficult to compare the two, but the question was: do humans get nearly as much training data as

You missed the point of the exercise. Of course it's extremely difficult to compare the two, but the question was: do humans get nearly as much training data as LLMs do? This analysis is good enough to say "actually humans receive much more raw input data than LLMs during their 'training period'." You're concerned with what the brain is doing with all that data compared to LLMs, but that's not the point of the exercise.