1) the check-out lines are too long,
2) the Cashiers are obviously "dragging their feet" in opposition to Management,
3) One or two Customers are "dragging their feet" as Consumers-Armed-with-Coupons, and, invariably, debate the price on each and every item, and
4) you've loaded up on things that you need/want/desire/but-can't-really-afford-except-outrageous-credit-card-terms...
So you push aside the basket, walk out, drive home, and make dinner with various and weird frozen foods cooked in one pot..."welcome, again, to your college-/first-job days!"
A: "Well, le'me see the nighty, bro'..."
T: "Cain't, bro...I Abandon Shopped when I saw the checkout line and had time to realize that I'd be paying for this basket, at 21% interest, for the next 10 years."
A: "Aw, that's cool, cool and W-I-S-E, bruh! So, you got the $5 you owe me, then, right?"