That really depends on one simple question:
Do you WANT to be alone?
If yes, you do have a life... You choose to be alone because well, you prefer to be alone, everyone has different ideas about what the optimal life would be like, some prefer being alone, others prefer getting shitfaced every weekend.
If no, Sorry... You dont have a life, I would recommend you try to hang out with people on your sparetime. Just start it easily by asking some of the people you socialize with if they'd like to go see a movie some time or something.
Personally I am so freaking sick of people saying that a person who never goes out with people on his spare time has no life. It's like it hasnt even occurred to them that not everyone are like them. This is speaking from personal experience, I used to just be with myself because it is what I enjoyed. I could not be bothered with having to care for others, when I was alone I could do whatever I liked, when I liked.
Now I tend to get out slightly more, but I still enjoy some "me" time every once in a while!
TL;DR: There's a huge difference between being alone by choice, and having no life.