Chanukah All Year Round
The Beis Aharon (p.45:) said, "Once, on Zos Chanukah, my father [Rebbe Asher of Stolin zt'l] asked his chassidim to sing, מסכת עלך הדרן חנוכה מסכת עלן והדרן חנוכה, 'We will return to you, masechta Chanukah, and return to us, masechta Chanukah.'" The Beis Aharon adds, "Who am I to explain my father's words?"
We certainly aren't on the level to grasp the depths of Rebbe Asher of Stolin's ideas and lessons, but one aspect of it could be to draw the impression of Chanukah for the rest of the year. At the end of Zos Chanukah, we have completed all the mitzvos of the holiday. We pray עלן הדרן, that the light of Chanukah should return to us. The spiritual impressions we gained on Chanukah and the miracles we attained should return and remain with us all year long.