There have been several times in ALL the series were severe traumatic events are forgotten by the next episode with no lasting effects in any series.
This is certainly true. Where I'm afraid we differ is that I don't think Star Trek: Voyager
was the same occasional offender as every other series in the franchise (excluding the original series, which was produced in a different era).
To put it simply, episodic amnesia wasn't an occasional conceit of a television series on Star Trek: Voyager
-- it was the modus operandi of the program.