"Yes, that definitely sounds like caffeine. Maybe the chemicals are similar because the periodic table must overlap at least a bit, and the physics as well...? Ah, but neither of those are things I'm at all talented in. I've just read a bit about them."

He can't give specifics as to why this chemical overlap exists, is what he means. But by now it's probably pretty clear that I've read about them is something that applies to a wide variety of topics. Nagito hoards information, even if he sincerely thinks his intelligence is nothing special.

"In my world, people put caffeine into a lot of things, but tea, coffee, and soda are very popular drinks that all have it. I'm not especially fond of high quantities of caffeine, but I do drink tea."

He also drinks a very strange soda that has sedative qualities, but that's outside the caffeine conversation.