A grande americano at Starbucks is a 16 oz drink with three shots of espresso. Have one in the morning and one in the afternoon and you are at six shots of espresso. That doesn't seem all that enormous to me.

75mg per shot = 450mg caffeine

That's a bit over the recommended limit of 400mg a day the Mayo Clinic, FDA, etc. recommend. Not sure it it qualifies as 'enormous' or not.

The amount of caffeine that humans require to live is 0 mg. So ...

Irrelevant to the question (How much is 'enormous'?).

It was a slight attempt to highlight that the conversation about a purely subjective thing is missing the point entirely. In the context of scientific discovery trying to qualify the outcome based on an individual's personal interpretation of descriptive words is a fool's errand. Attempting to justify one's personal habits or predilections is squarely in the flat earther camp of scientific belief.