Adopted from “Four Chassidic Masters” by Rabbi Dr. Abraham Twerski (p. 194-195):
The chassidim of the Tzaddik of Sanz were in Pressburg on Passover, guests at the Chasam Sofer’s table. Among chassidim, it is the custom to avoid eating gebrokts (matzah that has come into contact with liquid). This is a chumrah that misnagdim have not adopted; hence, the Chasam Sofer ate Kneidlach on Passover.
When the chassidim were served kneidlach, they were in a quandary, because they had never eaten gebrokts. One chassid did not eat the kneidlach. The other reasoned, “I’m sitting at the table of the gadol hador. Who am I to be more strict than he is?” and he ate the kneidlach.
When they reported their visit to the Tzaddik of Sanz, the latter said to the Chassid who ate the kneidlach, “You have earned Olam Haba.” To the chassid who had refused to eat them, the Tzaddik said, “You had better stand near me on Yom Kippur, and I will try to elicit forgiveness for you.”