1. They lack maturity

Some men aren't mature enough for a relationship at the moment. But that's OK. While it holds true for some men, maturity isn't necessarily indicative of whether they're single or in a relationship. Though some aren't mature enough to consider getting into a relationship, it is possible for a relationship to actually help them mature.

2. They like being single

For some reason or another, it's his choice, and while there will always be a handful of critics regarding that choice, it ultimately is his.

3. Their priorities are elsewhere

Things like video games or pornography, when over-consumed, can easily drive a wedge into the relationship and even destroy it altogether.

4. They're overly critical of themselves

Sometimes men don't see the great qualities in themselves, and it can even be up-and-down from day-to-day. For whatever reason, there may be something that has gone on that led them to be self-critical.

5. They don't really know what "love" is

"What is love? Baby don't hurt me, don't hurt me, no more."

In all honesty, the definition of love that a man sees at a young age can easily affect his own relationships outside the family he was born into. Maybe he has parents who fight a lot, impacting him to think love means arguing every day, or maybe his parents are very cuddly and show a lot of affection. It impacts what he looks for and wants for himself.

6. They're working on becoming a better person

While it's possible to become a better person during a relationship, it's perfectly reasonable for a man to want to become a better person before entering one because he wants to be at a solid level where he is mature enough to handle it.

SEE ALSO: 13 Thoughts A Man Ponders When He's Single In His Mid-To-Late 20s

7. They have high expectations and standards

Every man will learn through experience what to tolerate or what not to tolerate, and if it drives people away, so be it. He has boundaries that need to be respected, and he will know how to respect those boundaries, too.

8. He hasn't developed his "skill set"

Two important things in a relationship are the ability to cohabitate and be flexible. He'll benefit from knowing how to build things, having done his own chores in the past, and cooking for himself before, say, moving into a house or settling down.

9. He's more into his interests and hobbies

Every person has their own set of interests and hobbies, and those should never go away once you enter a relationship. It could be a matter of bad timing, but you can't convince someone to pay less attention to the things they love and more attention to you. They have to make that decision for themselves.

10. He doesn't trust easily

Trust is key to every successful relationship, and some people trust easier than others. Maybe he's seen through his own life that he's better off keeping his guard up because that's what he has been conditioned to do. It will take a long time for him to truly be vulnerable, and he's going to take his time to best prepare himself for it. Trust is not easy to build, but it's quite easy to destroy.

11. He's focused on his career

He's happy in his job, he performs well at it, great for him. It's something that makes him happy, and the right relationship will make him happy but also give him the platform to balance his own happiness while investing in another person. There's a learning curve involved here, and the more you learn, the steeper the learning curve gets.