From the beginning and till the end the human life, he is being alone. At the time of birth the child comes lonely (twins naaaaaa leave it, I say in common) and on death who will accompany HIM? No one. So you come alone & go alone. In the meantime journey, you may be having a number of friends, you wife, your children, but still don't you feel loneliness among the crowd?
I think there is a difference between loneliless & being alone. And it is when you are completely alone that you can truely release your soul and see who you truely are.
I think its perfectly normal if one chooses to be alone or wish to have some space for themselves. The most important aspect is what makes us feel comfortable or happy without hurting others. Time & again I have seen people being confused about marriage & companionship only to result in an unhappy marriage. So I agree, sometimes, there can be great enjoyment in silence.