If things only existed when thought about or noticed, than technically, nothing would exist because you can only think about one subject at a time, so all others not being thought about by others, mostly specific objects would be non- existent part of the time. And if quantum theory states that no matter can be destroyed or created, how would that work? Things are constantly under change, and, supposedly only themelves when somebody thinks of them as itself, so mentally your theory is correct, but I do not believe it physically. Also, i can Imagine that your Theory is incorrect...