"The bodhisattva vow is like a golden pot, the others like earthen pots. When an ordinary committment or earthen pot is broken, it has no more value; however, the bodhisattva vow, like a golden pot, can be remodeled and refashioned-its material remains precious."
-Kaul Ripoche (in Luminous Mind, p. 129)
In my own Catholic tradition, religious make vows in order to help others attain salvation. Sometimes those vows get dinged for one reason or another, and we call it a terrible thing, a shame, a failure. Tibetan Buddhism acknowledges many ways for Bodhisattvas to help others through countless lives. These vows to help others are never wasted, just transformed. How comforting, and, I think, closer to the truth.