No one’s calling you an idiot. It’s just very uncommon, and probably unheard of here. Remember it wasn’t that long ago when firearms could be privately sold in a similar way. If a purching party looks like there 12 years old, ok I get it, but that’s a case by case thing, not across the board. Also Walmart asks my birthdate because the computer prompts them as soon as ammo is scanned. I have yet to be asked for ID. Come to think of it, They do the same when I buy ?. Local shops have never asked me.
Your property, you can do with it as you please, including sell it and ask for ID
Welcome to the forum by the way