I attribute my success to this: I never gave or took an excuse.

The line frames “success” as the product of uncompromising personal responsibility: refusing to offer excuses for one’s own shortcomings and refusing to accept excuses from others that would dilute standards or delay action. In Nightingale’s case, the sentiment aligns with her reputation for relentless discipline, insistence on measurable results, and impatience with bureaucratic evasions—traits that helped her push reforms in nursing and hospital administration. The aphorism also suggests a moral stance: excuses are portrayed not as explanations but as self-protective narratives that impede duty, improvement, and effective leadership.