emotional hangover?

I don't know if this is true or not, but I've been told that a hangover is really just your body feeling normal again--that when you drink, your blood vessels expand and more oxygen and blood flows to the brain so you feel drunk. The next morning, when your blood vessels contract to their original size again and your brain is getting what it had always gotten previously, you feel hung over because of the difference between the amount of blood and oxygen you were getting the night before (abnormally) and what your brain is getting in the morning (the normal flow). I don't know if it's true, but for the sake of my analogy, let's all just pretend it is true.

Bars and clubs are the same thing for ones personal life. I went to a bar last night and had fun. I went alone (that is to say, single, albeit with friends) and I left...not alone. We danced the night away and drank and laughed and both seemed witty and interesting and perfect and then went off together.

Then I woke up and drove home alone. Like a hangover, I was no less alone than I was before I got to the club, the difference between what I felt alone in the morning and what I felt not alone the night before made the being alone feel all the more worse.