Does it make you feel bad? If not, then don’t worry about it. If so, perhaps it is something that you could work on. The socialization (or lack thereof) itself isn’t a problem one way or the other. The underlying motivation for not socializing is the issue. If you don’t socialize because you just don’t have anything in common with the people at work, or because you wish to keep your social life separate from your professional life, then I wouldn’t worry about it. But if it’s because of some emotional or psychological issue you’re having, then perhaps it’s something you should address.