What do you normally talk about in therapy? I'm curious.

I feel like therapy is a very useful tool, but I'm not getting much out of it right now. I think it's mostly my fault for not knowing what to talk about.

My therapist always starts off by asking me how my mood is, and I tell him. Then he asks how I've been since we last talked, and I tell him. Then he usually asks me what I want to talk about, and that's where I say I don't know.