Not having your ID

So I work retail, I sell lotto, cigarettes, and alcohol. Our state law requires ID for all alcohol purchases, our store policy is check ID for everything else if you appear under a certain age.

Why oh why do people go to stores like mine, wanting to buy something that needs ID, and not have their ID on them in case they get carded? It's not that big a deal. ESPECIALLY if you appear to be in your 20s.

I've got a regular who knows we need ID for alcohol who sometimes doesn't bring theirs, then throws a fit because we won't sell them the alcohol. I have a semi regular who complains about getting carded for wraps when they are literally in their early twenties.

Bring your ID.

Edit: So about the required ID for regulars. On alcohol we are required to scan ID every time, we are not allowed to type in birthdays unless your ID is being renewed, and you must have the paper temporary ID AND the old ID for us to be able to take it.

I know these people are old enough, but I am not in a place where I can risk my job. They need ID.