EDIT: Go easy on them, Luv2Dance. Not all of them are saying it in a bad way. Me for example. If I was close friends with, lets say another boy my age, so right now he'd be 19. If say, I hadn't seen him for a year, and I saw him right now, and he was a woman, he even had a sex change. I might say to him, "but to me a part of you will always be male." Because that would be the truth, I did cherish him in the past when he was a male, and that part I will always cherish. And I'd still love him as a woman, but to me he'd be the same guy that I always loved. And eventually, I probably would consider him a woman, but probably, I would, due to habit, accidentally refer to him as a man every now and then. But I'd still love him, with all my heart.
Yes, some of them do say it to be mean, but not everyone.