I believe you, Tiny.

Did you follow the Optima procedure for a deeply discharged OPtima/AGM battery?

https://www.optimabatteries.com/en-us/support/charging/resuscitate-deeply-discharged-battery

I saved two 6v Optima destined for trash, after the dealer tried a deep discharge, and failed to revive them.

I am glad I did not let the dealer throw them away.