I don't recall seeing it, but of course my failure to recall it could be additional evidence in support of your "short memory" supposition.
The CLAIM is that only that which can be percieved/measured/proven/demonstrated/predicted/tested/etc should get CREDIT for being real.
Are you making that claim right now? It doesn't look familiar to me. Should I recognize it as being identical to or a slight variation of some famous claim?
Regarding the statement that you introduced with the words "The CLAIM", if I cannot disprove it, then should I take that as good enough reason to accept it? I presume that you have available a rigorous demonstration that "The CLAIM" isn't silly, because if it is silly then, as you say, if it's silly then even though I might not find or construct a disproof of "The CLAIM", the absence of a disproof isn't very significant if the thing to be disproved has been shown to deserve the label "silly."
Is "The CLAIM" something that you consider to be self-evident? Alternatively, is there some process for deriving it from self-evident assumptions?