Head and Heart Never Agree

Why does the heart long for what it cannot have? Why does the head try and logic out every emotion, everything that might give a person hope? Why does your head tell you its not possible,that it'll never happen, while you heart continues to hope? My heart wants someone it cannot ever have. If someone shows the slightest interest in me or if i get told that someone likes me, theres always a way it could have been misinterpreted. Misunderstood. A mistake. Theres always something that says its too good to be true. Logic tells me that its just cause i want it to happen that i see the signs,but my heart tells me that they're real. That i'm not making things up to ease my loneliness. Why can't my head and my heart get along for once