When I finished my weekly shop in Hell (AKA Tesco), I pushed my trolley up on the pavement by the parent/child parking instead of putting it back in the bay. It only occurred to me today that I've been doing this ritual weekly for years now for the following reason: to announce to the next parent "Here is one of the four trolleys at Tesco that isn't wonky and has a child seat. You're welcome." I have no idea if that's why other people do it or if anyone knows this secret code, but I keep doing it just the same.
Today I went through a dozen trolleys before I found one that had four working wheels, an intact child seat, and that wasn't permanently attached to four other trolleys. Every single trolley at my local Tesco forces you to drag it to the right if you want it to move forward or anything resembling a straight line, so despite all the effort you go to finding a decent trolley, it's still going to be wonky.
It's not like Waitrose where every trolley is solid gold and gives your child a mild tranquilliser, lulling them into a happy dreamlike state whilst you get your shopping done in peace.* I never have to go on a trolley hunt; they're all lined up, gleaming and ready for me. Of course the downside is that my weekly shop costs about 1/3 more at Waitrose, but this is the price you pay for buying tomatoes amongst the beautiful people.
*(I'm possibly exaggerating. But my word, Waitrose is fantastic.)