Necessity

How to tell you're a grown ass man: all of your thermal travel mugs are in the dishwasher, and rather than go without coffee, you take one of your daughter's thermal mugs to work instead.  After all, going to work without coffee is NOT AN OPTION, and the thought of a work day filled with snarky, coworker barbs is NOTHING compared to a work day without coffee (i.e. my preferred caffeine* delivery system).

*Caffeine: an amazing legal stimulant that allows people to get to work/school on time, keeps the digestive tract humming along, is a major headache antagonist, allows one to find the upside to their very existence, encourages conversations with coworkers/classmates/peers you would normally find intolerable, gently prevents sleep without all those nasty murderous rages and demonic hallucinations associated with other stimulants, and is the major cog that drives the Earth's economic engine.