"must be so unreasonable not wanting to q for half hour cause you are disorganised"
Oh the irony. If you were more organised then you would not need to go to the shop during the busiest part of the day, and then be annoyed by people who might want to natter, or make sure their shopping is packed before they pay. Maybe find an extra five mins in the morning to buy your lovely shop bought sandwich then??
And speaking from a checkout lady POV, it is nice to be able to chat to the customers who might see only my face in the day, as everyone else is too busy, or understands that some people don;t want their money and purse to hand as they want to pack first, or just might have other hidden issues that hold them up.
If I want to rush I go to the self serve tills now.
well, I try. They are even more evil than any ditherer or rushed person.
That said, if you just have one sandwich, I would ask nicely to queue jump. Rarely do people mind, and I (I don;t work on checkouts anymore) never minded when sat there on the checkouts.
If I have a massive shop I sometimes even let people queue jump if they have less than, say, three items. They are, TBH, the ones normally in a rush.