Commentary for Kiddushin 62:5

Rabbi Tarfon had a mother: It is found in the Yerushalmi (Yerushalmi Kiddushin 1:7:7): Once the mother of Rabbi Tarfon lost her slipper in her courtyard. So she out from her couch to find it, and Rabbi Tarfon went and put his hands under her feet on the ground so that her feet would not get soiled; and she treaded on his hands. And also found in the Yerushalmi (Kiddushin 1:7:8) is that each and every time Rabbi Yishmael would arrive from the study hall, his mother would wash his feet and drink the water. When Rabbi Yishmael heard that she would do this, he refused [to do] the thing. [That was] until she went before the Sages and complained about her son, Rabbi Yishmael; that he was not fulfilling the commandment of honoring [parents]. And the Sages were confounded about the thing and asked Rabbi Yishmael. So he told them the story, and they commanded him to let her do [what] she wants, and that [her] honor was in this way.

R. Tarfon helps his mother get in and out of bed (yup, he’s the Jewish Oedipus) and doing so leads him to think he’s really the greatest at honoring his parents. He thinks he’s so great at it, that he goes and brags in the Bet Midrash. There the other rabbis put him in his place—really honoring your mother means not shaming her when she acts crazy in public, even when she causes you a financial loss.