It's this idea that came about from the wolf of wall street, then got very popular among what I'd call 'linkedin-bros', who are always posting 'motivational' stuff. The idea turned into you ask someone to sell you a pen, to see how convincing they are/how good of a sales person.What does that even mean?
When you have to sell yourself the pen, you've got to convince yourself of whatever it is that you want, I guess?