The guy is worried the girl and him won’t work out, even though he knows that she likes him too.

Ergo, he fails to chase her, as it is hard for him to believe that they could actually be in a relationship.

The reality of being in a relationship with someone is a lot different than the concept of dating them.

He believes she is above his league, fearing he won’t match up to her nor deliver if they were to date.

This frightens him to the point he chooses not to chase the girl or keeps procrastinating.

He keeps thinking about what it would be like were he to date the girl, fixated on their different backgrounds and how far apart they are in looks.

He is so fixated on the differences he has with the girl, he is too afraid to chase her or move forward.

He doesn’t want to set himself up for failure.

The last thing he wants is to chase the girl he knows likes him, only to find that she is now so aware of their differences that she is no longer interested.

This is scary.

This is wasted effort.

He would much rather not take that risk.

There is the fear the girl exposes his weaknesses.

In chasing her, she finally sees through his facade.

He isn’t as confident or arrogant as he portrays himself to be.

He isn’t as talkative and extroverted as he portrays himself to be.

Perhaps he has a habit that he knows she would disapprove of once she got to know him better.

These are weaknesses that he doesn’t want revealed.

He would be too embarrassed if they were exposed.

In light of all this, he decides that it would be better not to chase the girl.

A guy fails to chase the girl he knows likes him when he is torn between her and someone else.

There is another girl in the picture that he likes too.

Though he is single, he thinks about the girl regularly.

The girl could be in a relationship of her own.

Nevertheless, he waits.

He hopes that she leaves that relationship and ultimately be with him.

He has been patient this long and every time he feels like perhaps he should move on, the girl comes back into the forefront of his consciousness somehow.

She is a best friend or a work colleague.

This crush he has on her is strong.

The conversations he tends to have with her are not like the conversations he has with other girls or other people in his life.

They are far more intense.

He gives her priority.

As long as he cares about her more than you, he fails to chase you and waits on her.