What is the one thing that an Acharya does that no one else can?

Did Ramanujacharya or other great Acharyas of the past celebrate their birthdays? There seems to be no record of it. Did God, when He appeared as Rama, Krushna, and others, celebrate His own birthdays? There is no record of that either. Is it meaningful that I celebrate my birthday? If someone does loka-upakaram (acts of service for the welfare of all beings), perhaps such occasions may be celebrated. But as for me—there is no record of any great achievement. Everything that has been accomplished is through your interest, drive, donations, support, hard work, enthusiasm, and dedication to doing what is right.