Several people I know are what some might call alone and perhaps lonely.  They are single, whether through divorce or death.  Some have never been married and have always been alone.More... 
Before I start getting all kinds of mail on the subject, I know being alone doesn’t mean that you’re lonely.  You can be married and very lonely.  I was once but I’ve never truly been alone even then. 
When I’m supposedly alone at home, I’m not.  My ghostly friends come and go through my life, some at very odd times.  I welcome them.  They’re company and more.  They’re really good reference material.
Night before last, Claude and I were sitting watching TV and talking when Madeline went hotfooting it over to see daddy.  The lights were on and I could see very well when Mysti, my little ghost dog, stepped over and into a duck-duck stuffed toy Madeline had just deposited on the floor before hightailing it to daddy.  When Madeline put her back to the sofa and sat down, she then turned to look at one of her favorite toys and where her sister had just managed fading through, her duck-duck.
It’s was an unexpected joy to see Mysti even for that tiny moment.  Seeing ghosts that you love only makes you more aware of the afterlife, of living on and of still loving and wanting to visit with those you love that are still physical.
Lonely is not being alone at all.
Da Juana