Why would I need to verify my age when having a mattress topper delivered?

Posted by tobotic@reddit | AskUK | View on Reddit | 30 comments

Had some Silentnight mattress toppers delivered today from Amazon and the guy from Royal Mail needed to verify my age. Didn't need to see id as I'm apparently sufficiently elderly looking. Any idea why? They're comfy, but I don't know if they count as an addictive substance.