" I never drink coffee after 3.48 p.m. It interferes with sleep. Caffeine has a half-life of three to four hours, so it’s irresponsible serving coffee at 7.00 p.m. unless people are planning to stay awake until after midnight. Which doesn’t allow adequate sleep if they have a conventional job. "

― Graeme Simsion , The Rosie Project (Don Tillman, #1)