Almost every man wastes part of his life in attempts to display qualities which he does not possess, and to gain applause which he cannot keep.

Johnson’s sentence targets the vanity and social performance that, in his view, commonly distort a person’s life. He suggests that much human effort is misdirected toward projecting an image—pretending to virtues, talents, or status one lacks—rather than cultivating genuine character. The “applause” sought from others is doubly futile: it is won on false grounds and, even if obtained, is unstable and cannot be securely “kept.” The remark fits Johnson’s broader moral outlook, skeptical of fashionable reputation and attentive to the costs of self-deception: time and energy spent on display are time stolen from real improvement and durable satisfactions.