LOL - I was thinking the same "Never a stupid question..." but paraphrase it as "Never a stupid question, only stupid actions sometimes".
There are a few basic or golden rules with multimeters. The first I teach is NEVER do a resistance measurement on a powered circuit. (The 2nd is never try to test battery or source current capability by connecting an ammeter across the terminals.) Usually DMMs blow. If lucky, only the internal fuse blows, or other DMM scales may still read ok.
Ironically the DMM read true - any PSU or battery should ideally be zero Ohms (impedance).