Sometimes I think it could be the constant reminders that bother more than the loneliness itself. Everywhere I go, someone is on a cellphone, or holding hands/riding bikes/etc with a good friend or lover. When I come home from a long day of work, I can hear the laughter (or sex) shared by neighboring couples. When I turn on the TV, there are relationships presented in some fashion. Even on Food Network, you'll find couples. At work, you can over-hear co-workers talking about their social/love lives. So, with all of this, you can't help but ask yourself what it is that you are or not doing that all of these people have done. That question in itself is a little bit irritating to not have an answer for. Frankly, I think it is a simple thing for many of us, but we will not admit and face that we've lacked the courage to confront it and change our situations.