When you feel attracted to someone, it is because your subconscious is picking up on cues that you are compatible. This could be anything from their body language to the way they speak. Your brain is hardwired to want to mate with someone who is a good match, so that you can have healthy offspring. This is why you might find yourself attracted to someone who is not your type. Your brain knows that they would make a good mate and is trying to ensure the survival of your species!