The ice cream truck pulled up to our block yesterday. Same jingle. Same long line of kids.

Jake and Mia ran over with crumpled dollar bills. Five minutes later they came back empty-handed.

"The truck doesn't take cash anymore," Jake said.

"What do you mean?"

"Card only. Or some app. The guy said cash is too much trouble."

I walked over to see for myself. There was a sign on the window: "NO CASH ACCEPTED. CARD OR VENMO ONLY."

The ice cream guy shrugged when I asked about it. "Cash is a pain. I have to count it. Store it. Take it to the bank. This is easier."

Easier for who?

I came back to the kids. "So what did you do?"

"Nothing. We don't have cards."

"And that doesn't bother you?"

Mia looked confused. "Why would it?"

"Because your money isn't good enough anymore."

"But Dad, nobody uses cash. It's old."

"Says who?"

"Everyone at school. Cash is gross. Cards are clean."

I pulled out a twenty dollar bill. "This is money. Real money. It works anywhere. Nobody has to approve it. Nobody can track where you spend it."

"But it's paper."

"So? It's freedom. When you pay with a card, someone knows exactly what you bought. When you bought it. Where you bought it."

Jake thought about this. "Like when Mom uses her card at Target and they email her coupons?"

"Exactly. They're watching everything you buy."

"Creepy," Mia said.

"Now imagine you can't use your card. Maybe the internet is down. Maybe your bank freezes your account. Maybe the government decides they don't like what you're buying."

"Then you can't buy anything?"

"Right. Unless you have cash."

"But the ice cream guy won't take cash."

I showed them the Bitcoin wallet on my phone. "This is digital money that works like cash. Nobody controls it. Nobody can stop you from using it."

"Can you buy ice cream with it?"

"Not yet. But maybe someday."

We walked back to the truck. I used my card to buy them ice cream. The whole transaction was logged. Tracked. Filed away.

The kids didn't mind. They just wanted ice cream.

But I knew we'd lost something that day. Something we might never get back.