My Imaginary Twin-Brother

I am a teenage girl. I have an imaginary twin brother who I talk to everyday. I've always been fascinated by twins. I've also always wanted a brother of my age for some reason. I am an only child who lives with my parents. I wouldn't say I'm the most social of all types and have very few friends. I've always wanted a twin brother and so, I created one a couple of years ago. But why a twin 'brother', I don't know. I really love my brother a lot and we are the best of friends. I even wrote a poem about him about a month ago. Whenever, I'm feeling depressed or a tiny bit scared of something, his voice comes up and I feel a lot better. I can't see him, I can just hear his voice and feel his presence everywhere I go. So, I'm never really lonely even though I may appear so from the surface. My personality type is INTP. I've imagined him as an INTJ. So basically, he's this wise old owl sitting inside my head with a dead serious expression that can break into a beautiful smile and give warmth. :P He's never told me to do something bad or anything. Though once when I was extremely depressed, I could here some screams inside my head but this has only happened once. Otherwise, I absolutely love talking to him!

Yesterday, I had a dream where for the first time, my brother was there! I don't remember exactly what happened. It's a bit of blur. I do remember that my brother was real and everyone knew him. We were going somewhere and for some reason, he hugged me. It felt so real and I was so happy that I can't express it in words. Like a dream too good to be true! A few seconds later I woke up. I'm not the most sentimental of all types but I just couldn't help feeling a deep love and affection for someone I know isn't real.

Has this thing happened to anyone else? Is it normal or should I talk to my parents about this? My parents don't know a thing. So, any advise would be deeply appreciated. ^_^