Wait, wait, wait... yeah, I was wrong. I remember bags of milk. In Colombia. I remember them being the stupidest things ever. It's just a bag of milk. You cut a corner off and you better use it all.
I hate to break it to you, but in the late 80s the dairy producers here in BC tried to stop selling milk in cartons and jugs, making only plastic bags of milk available. There was a huge backlash from consumers, and eventually the dairy companies brought back the cartons.
Heh heh. Great movie that! I've got it on DVD. The coke bottle that falls from the sky, and the bushman who goes to find the edge of the world to return it to the gods... The Gods Must Be Crazy on IMDb
Although I realize it's very uncommon globally, I still get amused when people are surprised about bagged milk. We've had it here in Ontario for decades -- I don't actually remember a time when it wasn't available. I still prefer milk in cartons, but that's mostly because you can only get bagged milk in 4L packages (3 bags) and we just don't go through that much milk here most of the time. Plus, you can't get the good stuff bagged.
And do the people who are actually familiar with this concept even refer to them as "bags"? I've always referred to it as being a "packet" of milk, not a "bag" of milk... The word "bag" to me just implies something much bigger somehow, like the shopping bags I'd use to carry the milk home from the supermarket. And there's another thing actually: when it comes to carrying shopping, for me, plastic bags are the norm, not those weird flimsy paper sacks!
Yes, we refer to them as bags. But that's almost certainly one of those Canada vs. UK linguistic differences, like how we buy bags of chips while you buy packets of crisps. The only thing we call packets are small packages of things, like individual-sized packets of pepper, salt, ketchup, etc. like you'd find at a cafeteria.