No, you are not abnormal to want to be alone most of the time. You are just a solitary, non-social type of person. You will notice I put it as "non-social", rather than anti-social. There is a difference. Anti-social people hate other people. Non-social people prefer being by themselves, but don't hate other people. I am another non-social person. Occasionally I attend family functions, and I do talk to people when running errands, or to neighbors when I am out in the yard without problems, but these situations are by my choice. The rest of the time I am alone by choice. I do have contact with others thru the internet, but again, that is thru my choice. I like being alone. I found out decades ago that being with people too much of the time was too stressful for me, and that I didn't like constant contact. Fortunately, I live alone now. Unfortunately, my elderly father is an extrovert who can't grasp that anyone might actually like being alone, so in spite of my constantly telling him that I like being alone, he is convinced that I am miserable because I am alone. Some things must be endured.
Anyway, enjoy your solitude.
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If a man does not keep pace with his companions, perhaps it is because he hears a different drummer.
Let him step to the music which he hears, however measured, or far away.--Henry David Thoreau