It could be a symptom of anxiety, not that you're staying up thinking about things you are anxious about, but I believe the brain chemistry of the condition "anxiety" often leads to being more talkative at night, a night person, thinking heavily at night preventing sleep, etc.
I'm not saying you have anxiety (just an awareness of how little things one does can often be actual symptoms for slight mental conditions can be enlightening for a society that only knowingly experiences fever, cough, etc. - more tangible symptoms), and if this was the main symptom you would be FAR from needing treatment, but I can suggest a technique that works for me when I go through fairly severe bouts of this.
Think about nothing.
It's actually pretty hard to do, but is very enlightening. It also takes talent and skill, a real feat of intelligence thinking about nothing is! heh, but really, do try it, not that I'm saying it isn't boring... Of course, sleep often is.
Edit* Oh, I thought this was the social section and not the medical section.. I wouldn't have been so ad hominem about things if I noticed that, nonetheless I'm leaving this post here because it could help. I could have easily referenced insomnia as being an obvious symptom of anxiety, but as far as being "more talkative" at night, I couldn't reference it so easily other than the fact that I distinctly remember being asked that in a psychiatrist's office during an anxiety diagnosis session.