Your not necessarily crazy for the reasons you stated
here, Charlie. However....(ha)
Simply plugging and unplugging the receptacles might've removed a layer of film oxidation from the blades and allowed for a little more conductivity.
Other reasons for it, too. Alongside all is that
sometimes there is a change of sound and for merely that reason we describe it as 'better' when it's only different. We've ALL fallen in that trap - even if some don't know it or refuse to think it can be so.
It is what is is. If it sounds better to
you, then it is better
