Michael Coslo wrote:
At the risk of being both a dullard and messing up all the fun, does
not every destructive interference have to be balanced by a constructive
interference, which in turn leads to a condition of "Okey dokey?"

Yep, any destructive interference toward the source is exactly
offset by constructive interference toward the antenna. If one
takes time to calculate the component phasor voltages on both
sides of a Z0-match located away from the source, the constructive
and destructive interference is obvious.

A canceled wave needs a reinforced wave, and then nothing is lost,
nothing is gained.

Exactly. The reflected energy that appears to be lost as
destructive interference in the direction of the source
when a Z0-match is achieved, is recovered in the forward
wave as constructive interference energy traveling toward
the antenna.
--
73, Cecil http://www.w5dxp.com