I used to snoop around & hunt them down. I'd start with a general visual "size of the box" assessment, then assess the weight followed by a gentle shake.
If it felt/sounded interesting I'd cut the paper silently with a razorblade so I could peek inside. This stealth operation could be carried out quietly & the paper could be resealed easily if the cut was made along the edge of the box.
I revealed this method a few years ago when we were reminising at the dinner table & it was a complete surprise to Mom & Dad 'cause I knew they would have told me if they knew; everyone was being just a bit "too honest" if you know what I mean.
A PC comes in a box that would be just the right size for Shaq's sneakers.