Somebody who is Transsexual (Like myself) is somebody who is in the wrong body. Either males born in female bodies or females born in male bodies. For a comparison, imagine you just woke up one day and you were suddenly female when you've been male your entire life, and everybody treats you as if you were always female, and just looks at you weird if you express even once that this is not the case.
At least, that's how I'd describe it when it comes to myself. It's not a pleasant feeling, and I want to take steps to correct it whenever it becomes reasonable to do so.