So, let's continue with the halachot (halachic laws): the Gemara in Masechet Berachot says that although bread includes everything, you don't have to say any beracha (blessing). There's one exception, as you know: the beracha of the wine, on yayin (wine). The question is, why? Tosafot says it's because wine is chashuv (important), very chashuv; wine is very chashuv. Why is it very chashuv? Because it has its own beracha. Although it should have been a juice, like all other juices, you could say Shehakol (all things exist by His word), or you could say ha'etz (of the tree), maybe. Maybe, like olive oil, this one has its own beracha. The question on Tosafot is: So what? It has its own beracha outside of the bread, but the bread should still include everything inside the Seudah (meal). And don't tell me that wine is not part of the Seudah, because people who drink wine like drinking wine with their meat. Don't tell me it's not part of the Seudah. So who cares that it's chashuv? It has a beracha; it makes no difference. It's a little bit difficult.
The Rosh has a different aspect of why it's chashuv. This Rosh is very interesting. You're going to pay attention to, really, all the things that we do with wine in our calendar, in our religious things. You don't need the wine. If you think about it from a cold perspective, even kiddush that we do al hayayin (over wine), you don't need wine. Al pi haTorah (according to the Torah), you have to make Kadesh (sanctify) the day of Shabbat. Who said you need wine? The wine aspect of the kiddush came later, with the Chachamim (sages), who said, “You have to do kiddush on wine.” Why? Kiddush is the beracha of Mekadesh HaShabbat (Who sanctifies Shabbat). It has nothing to do with the wine. The wine came to give a stamp of chashivut (importance) to that mitzvah (commandment). We see this at a wedding, for example. Why do you say a beracha on wine at a wedding? It's completely unnecessary. You can't get married if you don't have wine. It's just to give chashivut. Berit milah (circumcision). Why do you do that? You don't need to do that. If there's no wine, you can still have the berit milah. So where did this come from? It's just that it's so chashuv. It's like saying that in some places they bring the baby on a silver tray. What is that? It's chashuv. You show chashivut to the mitzvah. That's all. Same thing with the wine.
It's interesting that out of all the ma'achal, all the foods and beverages that exist, the only one that was picked for that is wine. And over there you create a new beracha. Says the Rosh, that's what it means that it's chashuv and it has its own beracha. It has its own beracha that whenever you use it, you say it. It's the same way over there: you say it. So, too, inside the Seudah you say, it became so chashuv that it has its own beracha that you say it even when you don't need to, kind of. Unless that would be the explanation for why we say the beracha on the yayin and even in the middle of the Seudah.