Defenses

Most people have been hurt in their lives by one person or the other. This causes people who have suffered severely broken hearts to shut other people from their loves. You are probably single because you are afraid to make the same mistakes

Fear of rejection

Again many people are single because of the fear of being rejected. Some people are afraid to approach girls because they think they are not good enough. These people might remain single because they never try to talk to the person they like.

Pickiness

Pickiness can be the main reason why you are still not in a relationship. You may think that many people are good enough for you. What you must be aware of is that there is nobody perfect. The earlier you make a choice, the better.

Low self-esteem

Many people in the world today suffer from low self-esteem. Low self-esteem is when an individual thinks little of himself. Low self-esteem will prevent you from approaching the girl you so admire.

Fear of competition

As a guy, you may be single because you are afraid of competition. Many guys are afraid of entering into a relationship because they do not want to share or are afraid of other guys trooping into their relationship.

Isolation and Routine.

If you love to be alone, this will prevent your chances of getting a girlfriend. Those who are sociable and go out to new places have higher chances of getting into a relationship.

Source:mcmnt.com