Since my expectations sometimes conflict with my subsequent experiences, I need different names for the thingies that determine my experimental predictions and the thingy that determines my experimental results. I call the former thingies 'beliefs', and the latter thingy 'reality'.

You ought to admit that the statement 'there is "the thingy that determines my experimental results"' is a belief. A useful belief, but still a belief. And forgetting that sometimes leads to meaningless questions like "Which interpretation of QM is true?" or "Is wave function a real thing?"