Needs To Address Their Reaction To No Address

(I am a Canadian tourist in the USA, and I go to mail something to my mom. I get a box and fill out all the information on the sheet they give me, but when I get to, “return address,” I’m not sure what to do. I have only ever sent mail from the place I was living, and always knew a return address as the address it was mailed from. Since I am not mailing from where I live, and have no address here for it to be returned to, I approach the postal worker to ask about it.)

Me: “I’m from out of the country, so I don’t have an address here, so I’m not sure what I should put in this section.”

Worker: *with an absolutely disgusted expression* “You don’t have an address?!“

Me: “Not in the USA, no. As I said, I am from out of the country, so I don’t have an address here.”

Worker: “You have to put a return address! We won’t deliver it if you don’t! YOU HAVE TO HAVE A RETURN ADDRESS!”

Me: “Um, okay.”

(I ended up putting my mom’s address as both the recipient and the sender. She eventually did get the package.)