It's why you do it and what you want from it. A friend of mine is transitioning and I'm learning so much from watching her progress. She genuinely has dysphoria among other unrelated issues but I see the difference between her and me. That doesn't take away from my situation which I put more like "I'd rather be" as opposed to "I have to be". Even with all that she wants to keep her manly part and I could care less about mine. I joke if it were gone I'd have one less thing to hide and clothes would fit better. Those would be my main thoughts. Transitioning really would just be a preference for me not a necessity. A long time ago I didn't think that was enough reason. Now I see it can be. Seeing how comfortable I am spending most of my time as a woman the reasoning behind it is kind of less important now. It would just feel right to me to transition. I guess that's how I know what I am.