You have answered your own question. They feel they are trapped in a body that does not match their gender.
Originally Posted by Lion26
somewhat, ,i agree. all my life (before my transition) i felt "wrong". And for me I never wanted to be a "woman" I just want to be myself. And as far as identity goes, its female, as for those who only see things in black and white, u can say I am a woman, but more so I am a transsexual woman. No amount of any change or surgery will make me a natural born woman, its closer to the mark than identifing as male.Im happy who I am and thats what matters most if life. As to why, some knw from birth some discover the desire later in life. I was born XXY, and my parents never even told me, I found out later on and it became clear to me, what I was feeling, the unhappyness, the misconception on every little thing. Before my change and proper diagnosis with gender identity issues, I was misdiagnosed with bi-polar from multiple personality disorders, didnt get the proper care until I came of age and found out my klienfelters syndrom, and a doctor with expierence with the issues, my life was a daily hell, i would not be alive today if I had not made the change. And ive never been happier!!!!!