For a long time I've thought I don't have a penis like my father's one. After I discovered my transgender position, I connected also this because I'm very attracted to vaginoplasty.
Some years ago I went to a gym and a boy showed me his penis after some time I went there with a she frIend. I quit the gym. When I got sick during a vacation, in a change room I was half undressing and a friend was watching. After some time I argued with him. 
These are all casual events that are accepting me my transition but the real reason is "I don't have my father's penis" and if I would go with a man I would choose one with giant testicles. How I tell this ? I remember where and the facts, but I'm not sure if is an abuse or not