No, the title of this post doesn’t refer to HQBH, although clearly it could. (Or can it: Can we define “heroism” with respect to One for Whom there are no risks to take?) Nor Yehudah haMakabi, nor Matisyahu, nor Chana or any of her sons, nor Yehudis…
The Beis Yoseif famously asks why we celebrate the first day of Chanukah. After all, the oil burning on the first day wasn’t miraculous, was it? It was only the additional seven that constituted the miracle. There are many answers to this question. When I was in grade school, a rebbe told of a seifer that was entirely a collection of 100 answers. Some show why the first day was a miracle — they only put 1/8 of the oil in each day, they put it all in, but at the end of the day the cup was 7/8 (or entirely) full. Or, one day to celebrate even finding the oil, or perhaps the military victory.
I want to give the Alter of Slabodka’s answer, but I want to present it on top of my own thought.
The miracle of the oil is an odd reason for Chanukah. In fact, it’s not mentioned in either of the books of Makabiim, not in Megilas Taanis, not in Josephus, not until the gemara. But what makes it odd is that it’s not a neis in the traditional meaning of the Hebrew term. A neis is a banner, a standard or a flag. When used to refer to miracles, it refers to the fact that nissim call G-d’s Presence to our attention. But the oil burning for 8 days could only have been witnessed by the Chashmonaim and the few believers who made it into the heichal (the Temple building itself) with them. Celebrating private miracles is common in other religions. However Judaism is proud of standing on the notion of national events, public miracles — nissim.
I would therefore suggest that when the gemara asks “Mai Chanukah?” it wasn’t because Ravina and Rav Ashi thought that anyone learning the gemara needed a remedial lesson in what Chanukah was about. Rather, it’s because Chanukah had to shift in meaning. Gone were the days of the Beis haMiqdash. Jewish autonomy was by that point ancient history. The authors of the gemara were living in a Babylonia where it, not Israel, contained most of the world’s Jews. Everything G-d gave us back from the Saleucids, He had since took away in the hands of the Romans. The question wasn’t “What was Chanukah made to be about?” But “What does Chanukah mean to us in the hear and now?” Chanukah was not made to be about the oil; as I argued last paragraph, we don’t make holidays for private miracles. But the miracle of the oil, and what it meant, is all that remained.
Now for the Alter…
The Alter of Slabodka says that the miracle of the first day of Chanukah is that oil itself burns. This is reminicent of the story of Rav Chanina ben Dosa’s daughter, who accidentally filled the Shabbos lamps with vinegar instead of oil one week. This was tragic, as Rav Chanina was so poor he lived off a qav of carob from Shabbos to Shabbos. (Carob grew untended, and was available for free.) Rav Chanina’s daughter was distressed by this mistake, perhaps because of their inability to afford wasted oil or vinegar. Rav Chanina answered her, “He Who made oil burn can make vinegar burn.” And the vinegar burned. (Taanis 25a) Similarly, the miracle that oil burns at all, as it did on the first day, is no less a wonder than it burning on the other 7!
Going back to my own edifice… Rav Chanina saw the supernatural burning of vinegar no more proof of G-d’s existence than he saw everyday within nature.
Similarly there was a heroic kohein who, back in the days when everything was falling apart around him, took a sealed jar of oil and hid it. He saw G-d within the natural course of events, even when they were flowing in the direction away from holiness. And that kohein, with full bitachon, trust in the Almighty, that “this too shall pass”, another generation would arise, and someone was going to need it. His bitachon made the first day possible, and according to the Alter of Slabodka, it is seeing the world as he did which underlies its observance.