And that's the story of how I completed my collection of dollar bills featuring birds from around the world.

Wow, I'm sure owl will be the first to tell you that sounds like an impeccable adventure.

Yeah, I know people like bird watching, but honestly, money featuring birds watching is a perfectly good hobby for those of us who are not really into sitting quietly in the woods.

You know what I mean?

Whenever you want to go out looking for bird money again, just let me know because two can play at that game.

Okay, we can stop with the bird puns.

You think I'm making bird puns?

That's cuckoo.

You're a real comedie, hen, Bridget. Please sparrow me, your mocking tone.

You know what? Let's take a listener question. Okay, I think we just got one.

Hi, my name is Alessio, and I'm nine years old. I'm from Italy. I have lived in three countries and I have visited dozens more.

Wow, man, this nine-year-old kid is better travel than me, a 39-year-old man.

Ciao, Alessio. It was kind of hard for me to understand if things were pricey or not. Whenever I went to another country because their currencies

were different. Yep. Okay, that's very good observation. My question is, why doesn't the world

have the same currency? And is it even possible? Wow, great question. We all know countries

have their own currencies, but we've never

stopped to think, what if they didn't? Yeah, I like how you're thinking here. What a great

thought experiment. Luckily, there are smart people who can help us imagine what that world would

be like. Like Hannah Gabriel, she teaches economics at Sacramento State University, and her specialty

is international trade, which means understanding how countries buy and sell from each other.

Hi, Hannah. Hi, Bridget and Ryan. So first question, for people who don't know the answer,

unlike me, I know the answer, but why do all these countries have their own currencies?

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