Musar על סוטה 79:16

Likewise Rabbi Abahu, despite his great humility, found that he had not yet reached the point where he may be fittingly called a humble person, as our sages told: "Rabbi Abahu said: At first I used to think that I was humble; but when I saw R. Abba of Akko offer one explanation and his interpreter offer another [to the audience] and he was not bothered, I considered that I was not humble" (Sotah 40a).