I'm not a loner, I'm sociable, but I'm very happy in my own company if OH isn't here. He's a long distance driver and he's certainly no loner either - he's comfortable working alone (much prefers that, doesn't like it so much when they send him out with a second driver), but when he's home, he's sociable.
Loneliness is very different, a friend wouldn't go on holiday on his own so doesn't go - it's very sad not to be comfortable in your own skin. I feel sad for people who won't stay alone in the house in the evenings because they are lonely. That way lies nights in the pub - not a good way to deal with it....