I get into anti-social moods myself where I don't want to see or talk with anyone, maybe that's a sign of aging, I don't know. But I also at times long for company and dialogue. Again, depends on the mood.
I like both periods of solitude and periods of being more social. Fortunately, my gf is the same way. I think a lot of people are that way, not most, but a lot Before I found a partner who had the same eccentricity, I was a lonely person for a while.
Now, when I am off by myself at my place and my partner off at her place, I tend not to be lonely. I work and live quietly in a very remote area. The wildlife around my home seem to accept me as part of their community.