I have noticed pictures and videos of UK grocery stores and the wide variety of goods available and how they seem to be jam-packed with food and other items.
It's not too hard to see how your average Joe or Jane would look at all of that and think " How could we ever experience food shortages when the stores are just overflowing with this stuff? ".
The problem is that the more sophisticated a system is, the more vulnerable and subject to any kind of disruption it is because it relies upon precision.
Back in the horse and buggy days, most cities were ringed by farms so that transport of produce took the least amount of time to get to the markets. Due to modern transport, that is no longer necessary. Fuel rather than horses or mules is required for food transport and so presents more of a problem if fuel shortages occur.
I highly recommend the book " King Rat " for how mostly British but also Australian and American POW's grew food without traditional fertilizer. Basically they had a system where urine from the POW's was collected and then to which water was added to reduce the acidity and then spread among the cabbage and eggplants they were growing.
Commercial farms would no doubt be given priority when it came to fertilizer shipments, but home and community gardens perhaps not so much.
I know that's quite disgusting but it was required to supplement the meager rations they were given by the Japanese.
On a more humorous note, I watched an episode of " Columbo ", the one where the singer Johnny Cash acted in. They were having a cookout and Columbo remarks to Cash's character about some chili they had cooked about how good it smelled. Cash's character told him here have some. Columbo eats a bit or too and then asks what is in it.
Cash's character replies " Squirrel meat, it's good ain't it " to which Columbo acts shocked and then politely says " Yea, that seems to make all the difference ".
You could just tell Columbo didn't really care to eat squirrel meat.
I watched the movie " Blackout " about a widespread power outage that lasted for about a week in the UK.
When the unprepared for anything neighbors came over to this guy's house because he was having a cookout that they could smell he could have told them that the reason it smells so good is because he puts a special ingredient in it. He could then reply " Roadkill, that is what gives it that extra something special ".
I doubt they would want to eat anything this guy cooked because no telling what he would put in it.