Where I was raised there wasn't a taboo over coffee as a "drink for adults" (something that I learned from American movies and found quite funny). When I was a kid I'd drink coffee with milk because I didn't care much about coffee, but nobody would bat an eye if I did... I also never understood that thing about people drinking coffee and getting energized. From what I learned, American-style coffee has about half the caffeine of the regular coffee we have here (Brazil), and not rarely I have coffee with bread or cookies before bed (if I didn't have dinner and I'm feeling too lazy to make something). It doesn't affect my sleep in the least and I never felt the least energized with coffee. I always thought this thing about caffeine getting you high was a joke from movies, but people in real life do seem to claim it :S (well, I do remember teens smoking oregano thinking it was pot and claiming to be high as well...)
ps: Nope, I'm not addicted to coffee. The regular breakfast here is coffee with bread and butter, but most of the time I don't have breakfast before leaving so I don't drink any coffee the whole day, and I go weeks without drinking it. If it isn't to have coffee with bread, cookies or biscuits, I don't have coffee at all.