Earlier quoted context omitted.
Very true. The last milk I bought was Darigold here in the US, and the sell-by date was sometime in March. I don't know what they're doing to extend its shelf life so much, but as a childless sometimes-uses-milk home, I love it, and couldn't care less about the exact dates.
Maybe you bought UHT milk? That has a shelf life of months.
Ultra pasteurized simply means that the milk has been heated under pressure at a higher temperature for a shorter period of time (280° for two seconds versus 167° at 15 seconds for standard pasteurized).