Have enough sense to know, ahead of time, when your skills will not extend to wallpapering.

Using the homely example of wallpapering, vos Savant underscores a practical kind of intelligence: accurate self-assessment. The point is not that wallpapering is uniquely difficult, but that many failures (and wasted time or money) come from overestimating one’s competence and discovering limits only after damage is done. The remark advocates foresight, humility, and planning—knowing when to learn first, hire expertise, or choose a different approach. It also gently satirizes the common impulse to treat every task as “do-it-yourself,” suggesting that wisdom includes recognizing the boundary between confidence and competence.