What your interlocutors are being quite vague about, TDLB, is that you haven't considered the full implications of the First Law.
That is, just because I have energy here does not mean the energy total of the entire universe has increase because I see an increase here. You even said so, yourself: "Energy can be transferred from one system to another."
So think about it: If there is energy here, what might exist elsewhere? There are particles and there are antiparticles. As the Casimir Effect shows us, the vacuum itself is continually fluctuating, creating virtual particle pairs constantly that then immediately annihilate each other.
In other words, everything adding up to zero is no different from nothingness itself.
Rrhain
WWJD? JWRTFM!
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