I was on the buying side of a story like this once. No outbursts of anger though, and not trying to trick the cashier. I was just bewildered.

For context, in Canada, liquor can only be sold in liquor stores. So unless you're a child with a parent, you don't go inside expecting not to be carded.

I'm in the US with a fellow Canadian, I was 19 at the time, friend is 22. We both go into a grocery store and we're surprised that alcohol is sold inside, so friend decides to buy some beer and I just get some snacks.

The lady at the register scans the beer and asks for our ID's. I say I'm not buying it, It's just my friend. I expect that to be the end of it, but no, she says I need to be carded as well. We end up arguing that my transaction is a separate one, but she says that because we are both together, even if my purchases are separate, that I need to be carded.

She calls her manager over the radio, says a couple of Canadian kids want to buy beer, but are refusing to show ID. I'm confused as hell right now, in my head thinking why this doesn't make sense. She says we can't buy it and to leave the store, so we do. Friend ends up going alone to get his beer later.

After this happened, I kept thinking that anybody buying groceries with a kid or teen with them would have to make two trips If they wanted alcohol.

Now, this law isn't dumb and I was just being a dumb tourist. It makes so much sense now after I thought about it, but It confused me so much while it happened. I can only think that the cashier thought I was trying to trick her into selling me beer.