So I've been living alone for over a year now and I've been single for roughly 1000 years (or maybe it only seems like it). When you are single and living alone you begin to develop a lot of routines in your life. Everyone has a routine but it's very different when you live alone, because your routine is never really interrupted. You can always watch what you want on TV, eat when you want, sleep when you want, be as quiet or loud as you want, and you don't have to accommodate anyone else.
The line between alone and lonely has a lot to do with what you do with your time and how you keep yourself entertained and happy (especially in a new place with less friends and no family). So not only do you develop a largely uninterrupted routine, but it also becomes pretty important to you.
Sooner or later you are in danger of becoming massively self-absorbed. That's probably about the point when you finally meet someone and have to re-learn how to accommodate another person's needs and preferences into your life. It's pretty much life's sick joke.
I mention this because most of us probably don't picture ourselves alone for any significant portion of our lives, and then all of a sudden we are. You don't even notice that you are becoming totally ingrained in your specific way of doing things until someone comes over and folds a towel wrong or something. Then you are forced to realize that you are deeply, deeply single and that is very, very depressing.
Just try to remember all this the next time you are alphabitizing pop tabs from third grade by type of soda. Someday you might have to throw them away to make room for that special someone's collection of mint condition Pogs.