Hi deathy!
At first I thought you were joking about it but seems you are not?
I've heard stories about imaginary friends you know. Most of them about kids. Some of them seem to be a good influence on them, other seem to be a bad influence too, but never heard story of someone older having an imaginary friend. I am intrigued now by your experience
BTW, don't think of you as a sociopath! I guess you are just more sensitive to other things that most of us people cannot see with the naked eye
I don't have an imaginary friend though, btw, not now, neither when I was a kid.