The Talmud (Shabbos 31a) relates how someone tried to get the great sage Hillel angry by continually interrupting him on Friday afternoon when he was in the middle of bathing for Shabbos. Although the man asked Hillel ridiculous and irrelevant questions, Hillel answered him patiently.
The Talmud says we all need to strive to reach this level of humility. That is, we are all obligated to work on ourselves to develop the total patience of Hillel whom no one could anger. See my book, “Anger: The Inner Teacher” (ArtScroll) for elaboration of a nine-step program for conquering anger.
Sources: see Rabbi Yechezkail Levenstein – Ohr Yechezkail, Midos, p.14