My parents’ long and happy marriage was a great ideal to live up to, but a tough one.

Williams contrasts admiration with pressure: a “long and happy” parental marriage functions as both inspiration and yardstick. The “ideal to live up to” suggests a model of commitment, stability, and affection that she values, yet “a tough one” acknowledges how exceptional such marriages can be—and how comparisons can burden one’s own relationships. The line captures a common dynamic in family narratives: exemplary parents can be emotionally supportive, but they can also set expectations that feel unattainable, especially amid modern realities of work, public life, and shifting norms around partnership. The quote’s poignancy lies in its honesty about gratitude without romanticizing the difficulty of emulation.