If you accidentally wash your money, it doesn't turn into mush. That's because it's made of cloth materials like cotton and linen, not wood pulp!
The bills in your wallet might be called "paper money," but if they were made from the same stuff as your notebooks or newspapers (wood pulp), they would fall apart the first time they got sweaty or rained on.
Most "paper" currencies, like the U.S. Dollar, are actually made of a special blend of 75% cotton and 25% linen.
Because it is basically fabric, the "paper" is much tougher than actual paper. This is why you can fold a bill thousands of times before it tears, while a piece of notebook paper would rip much sooner.
In many countries today (like Vietnam, Australia, Canada, and the UK), "paper" money is being replaced by Polymer.
If you accidentally leave a real paper note in the washing machine, the fibers of the wood pulp would break down and turn into a messy soup. But because your money is made of cotton/linen or plastic, it survives the spin cycle and comes out looking cleaner than ever!
"Paper money" is a bit of a lie - it's actually more like a very high-quality piece of clothing or a high-tech piece of plastic. This durability ensures that the same bill can travel through thousands of hands for years without falling apart.
