What's most often the reason? Because I don't know what's wrong with me :(
Most Helpful Guy
It could be any of the above. It could be she's just not found a man she's shares mutual attraction. It could be she has other priorities in her life. If I had to give an answer that's most likely the cause most of the time, it's probably going to be she is ugly, since even attractive women who are boring and/or arrogant will still attract boys.
And there is nothing wrong with you. Society puts pressure on people to get relationships, so for those who are left out, they might think something is wrong with them. For the vast majority of the cases, there's nothing. If that's your picture, you definitely are not ugly, and I'm not saying that because I fancy brunettes either lol.
Don't fret about not having a boyfriend yet. You are only 19, and when one worries too much about they, they inadvertantly and unknowingly give of desperation vibes.