Coffee isn't the only thing known to cause sleeplessness. MSG (and the various aliases they use to disguise it) does a fine job of keeping the brain humming all night. And they put it in almost every prepared food. ("Hydrolyzed vegetable proteins" and "Flavoring" are two words to watch out for in ingredient lists --these are usually other forms of glutamates.)
That's an obvious one, but paprika and vitamin C does it for me as well.
Significant tensions (illness, argument, etc.) with a family member (or yourself) or close friend will certainly do it, too.
