A moving insight by the Lubavitcher rebbe written up by Rabbi Yanki Tauber
Two? Oh, you mean the shammash. He doesn’t count.
Night after night, the shammash dutifully goes about his task of kindling lights. Each evening, he welcomes the newcomer and settles him into his rightful place in the growing row: two flames, three flames, four flames.... The shammash coaxes them to life and then stands watch over them, lest one falter and require a fresh boost of light.
Still the shammash doesn’t count. An imparter of light to others, he never attains the status of a Chanukah light in his own right.
Despite—indeed because—of this, the shammash towers above all the other lights of the menorah. To forgo one’s own luminary potential in order to awaken a flame in others—there is no greater virtue.