Jeff is right. It’s not the same as being totally alone and if you have dysfunctional family, it’s even worse when you move to escape them. I’d bet 90% of the population doesn’t really know what “alone” really means. However, even if you have a mate to live with, you can feel lonely. One of my worst episodes of loneliness was with my husband, when I lived & worked where I grew up. So I know both ends of the spectrum now. It is a basic psychological need to feel belongingness in society and just one person, a spouse, cannot fill that need. I’ve always preferred solitary activities, so now I am more content than I’ve ever been; just me, my little dog, tons of books, movies, good TV shows, my small Facebook posse. Even with Fibromyalgia, I am happier now than when I had the stresses of nursing, unsuitable marriage, my mentally ill family being close by and when I felt my biological clock ticking away with no resolution for that. So I’d say how much we feel happiness or not, depends on multiple factors, not just how many friends you have or if you have a spouse. Just one more thought: I’ve come to the conclusion that only children are able to develop much more resilience in solitude, than children who were not singletons. If you want to see more about human needs, look up Maslow’s Hierarchy on You Tube.