Interesting, I consider the difference between "alone" and "lonely" a lot. I feel like I have lived most of my adult life "alone." I moved from IL to Los Angeles at 22, lived with a friend from HS for a few months but then she moved out and I was by myself. That alone time at that point in my life really shaped who I have become. I was married for 11 years but the dynamics of our relationship dictated that I was the one who made the bulk of the decisions, plans, arrangements - and I felt lonely. 

I am a people person, too, but somehow I learned early how to appreciate my aloneness. Sometimes I wear it like a gold star ("Look at me, doing this alone - I'm a real grown up!") but sometimes I get so very lonely. Last night, for example - ordinary Wednesday evening, nothing of note happening - but I wanted to be WITH someone. I scrolled through the contacts list on my phone, searching for someone to call so at least I could talk to another human who likes me, but didn't find anyone. I fell into loneliness and the evening was long. 

I long to be not alone but most of the time I am alone and not lonely.