Another belief of mine: that everyone else my age is an adult, whereas I am merely in disguise.

Atwood’s line captures a familiar form of “impostor” adulthood: the sense that maturity is something other people possess naturally, while one’s own adult role is a performance held together by costume and convention. The humor in “merely in disguise” underscores how social expectations—competence, certainty, authority—can feel like masks rather than inner realities. Implicitly, the quote questions whether adulthood is a stable identity at all, or instead a collective agreement to act as if we know what we’re doing. It also gestures toward empathy: if many people feel similarly, the boundary between “real adults” and “pretenders” may be largely imagined.