I figured it went without saying, in the post below, that an obvious reason for being single is that someone's unattractive. I didn't say it because most guys already assume, wrongly, that they're single because they're not pretty enough. I'm not saying that you shouldn't work out or get rid of your unibrow or whatever to attract more guys. I just don't think it's as common a reason as other people do. We all know lots of guys who aren't all that to look at but still have a good relationship. Besides, a guy that you might not think at all attractive might be entirely smokin' to me.
We all also know guys who spend hours and hours in the gym (which is great if you just love the exercise: it sure beats hitting the booze) and are still unhappily single. Lack of physical attractiveness isn't the reason for those guys.
2 years ago