My boyfriend doesn't open up to me?

We've been together for over a year. I mean he talks to me if he's pissed off or stressed and stuff like that, but he had a troubles childhood, he was a foster a child. I barely know why he was a foster a child, or what happened. I've asked about it once or twice, and I've said if he doesn't want to answer he doesn't have to because I don't want to upset him. I want to respect him and his feelings. I just feel like I don't know half of his life. Will he ever open up to me? I just genuinely want to know because I want to know the whole of who he is and the person I love, not just what's occured while I've been with him.
My boyfriend doesn't open up to me?
Post Opinion