They don’t. No one does.
If not, perhaps you should reconsider...
It kind of makes sense that piggy banks are shaped like pigs, because the pig is a traditional symbol of wealth and abundance in some cultures. But in fact, piggy banks were around long before they began to be shaped like pigs
The term “spring fever” may conjure images of children bursting to get outside and play in the newly-pleasant weather, or even romantic couples swooning over each other, but the real spring fever is almost the exact opposite of those things.
We pretty much take it for granted that, when we spread a map out on a table, the top of the paper is going to be north. But if you think about it, there’s no absolute reason that should be the case.
Not if you plan on penning your memoirs or painting a watercolor masterpiece!