I spend all my time inside anyways, so night would definitely be an option, but I find natural light makes me far more productive. Besides that, my friends just... aren't night owls like I am? They stay up late, yeah, but I'm usually the one left awake at the end of the night.
I may be an introvert, but if I go too long without talking to my friends, in person or online, I get this really awful feeling, like there's a pit in my stomach. I just feel... empty, and I hate that feeling.
I think it might be linked to depression but I've never been officially diagnosed.
Sorry this one got kinda serious.