A girl : So, Tom, what is it that you do?
Tom : I write greeting cards
Summer : (She knew he majored in architecture and sometimes he draw the buildings at the office without letting people know. And she saw him reading a book, "The architecture of happiness". She knew he has been dreaming of making it as an architect, but he settle for the present, in this situation, she says)
But, Tom could be a really great architect if he wanted to be.
But, why "wanted"?, when we say "wanted" here, we imply that I don't think he wants or I'm not sure if he wants, but I'm just thinking of the imaginary situation and wonder what it would be like. But, she know he wants to be an architect deep inside. That shouldn't be the imaginary situation. So, maybe she could have said "he wants to be an architect, so at some time, he could be." But the reason she said like above, is because, she wanted to pretend like she doesn't know well about him. She didn't want to sound as if she knows everything about him, which could kind of sound rude. She didn't mean to be rude, so she was so cautious about the word she choose that she said "wanted" here.
Am I right to think this way?