Do delivery people know what they deliver?

Like one time I ordered an Xbox 360 and the guy KNEW what was inside the box. I didnt think nothing of it, but it came up again when I was at work and had to sign the package in for a co-worker, the delivery guy who came KNEW what it was. (videogames LMAO). But now I wonder, because my older bro one time ordered some....lets say...sexual gizmos...to our house and I wonder if the delivery guy knew what it was. Cause when I took the package of sexual gizmos for my bro, the guy didnt say much (usually he'd say some funny ****), but this time he just dropped it off and left...like he knew lmao! Just wondering...kinda bored at work and whatnot maybe. So do these UPS/Fedex/w.e know what we order?