I was going to say, "Don't get me started on shopping carts!" but you already have, so it's your own fault!

Things I hate about shopping carts:

1) They're required to have safety belts for children who ride in the little fold-out upper basket thingies. That's good from the standpoint of children versus concussions, but the belts and their snaps get all tangled up with other carts when they're nested together. Before you can pull your shopping cart from the stockpile, you usually have to disentangle it from its neighbor.

2) Most modern stores use some sort of rough surface material (cobbles, flagstones, corrugated stiff carpeting) in the area where empty shopping carts are kept. This is done so that you can't quickly evaluate the cart's performance. You don't know if it has a wheel with a flat spot or if it pulls to one side or the other until you've negotiated the roughly floored area and rolled onto the smooth main floor. By then, you're fifty feet from the cart storage area and, if you've drawn a bum cart, you have to decide whether to turn around and swap it out or to just live with it.

3) It's not the shopping carts' fault, but most of the people who operate them are idiots. The idea that an unattended shopping cart in the middle of an aisle might somehow obstruct other people's ability to traverse said aisle seems to be beyond the cart operators' conceptual skills. And when two morons who haven't seen each other in ages happen to meet in a grocery store aisle and decide to have a mini-family/high school reunion on the spot, just forget about doing any shopping on that aisle. Go on to the next one and come back after the two morons, their two shopping carts, and accompanying six children have finished their gabfest and moved on elsewhere.

BTW, there is a high-tech solution to the carts-leaving-premises problem Bert's thrift store decided to solve by making it impossible to push the carts through the doorway. Some stores' carts are equipped with electronically activated brakes which immobilize carts taken beyond certain perimeter points. Probably not something a thrift store could afford at this time but, hey, that kinda stuff gets cheaper every day.