One of the reasons I find it difficult being single is when I've had a bad day - at work, wherever, whatever - there's no one to come home to to tell about it. Someone else might offer me words of encouragement or just distract me with conversation about their day. At least I wouldn't be quietly alone with my own thoughts, dwelling on whatever happened.
NOTE: I know marriage offers no certainty of anything. But this post is just to let others know how singleness feels