Similar to me, I haven't watched any 9/11 documentary in years either, as it's just too intense, and I don't know what I would get out of it. Unless there is some kind of new information, I don't need to hear a bunch of information about what happened because I already know what happened and will never forget.
I do appreciate that shows continue to air, to keep new generations aware of what happened and not let it completely slip into obscurity.