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"Impossible" is a word that humans use far too often.
— Seven of Nine · Star Trek: Voyager

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker suggests people declare things impossible far more casually than the facts warrant. It reads as a mild rebuke, treating the word as a habit of giving up rather than a real limit. The implication is that many so-called impossibilities are only untested or unimagined.
Context reviewed