Why do you haunt my brain?

I keep seeing you in my dreams, asleep or awake. It seems like you're always there, looking at me from an angel I can't find. No matter what I read, hear or see, I just can't stop thinking of you. No matter where I go, it feels like you're always right next to me, holding my hand.
But my hand is always empty, and I always seem to be alone. There's no one there by my side, and the voice I keep hearing, is just my brain fantasizing about you. Though no matter what I do, I can't make it stop.
Why do you keep haunting my brain, Jonathan?