It’s a bit of hyperbole, but not much of an exaggeration. One iced tea 10 hours ago, OK, but if it were 2 iced teas after about 3 pm, I would be in trouble.
In grad school, I had this British friend, very British by his own admonition. One evening I did him a favor, and he asked how to thank me. Feeling a bit tired, and wishing to attend a yoga class later in the night, I suggested he make me a cup of tea. That is a very British thing to do. He selected an Irish breakfast tea. It was delicious! I had 2 cups! And I attended that yoga class, by golly! And then I vibrated for the rest of the night.
I do not drink caffeine after 3 pm now.