Vlad the Impaler was funny in a very horrible way. This little joke was his way of letting Benedict de Boithor's boss, the governor of Hungary, know that he better not waste Vlad's time with any ambassadors who couldn't think fast or who didn't know that absolute deference was expected of anyone who set foot in Wallachia. The part I didn't include was that the room in which Vlad received Benedict was full of the dead and dying impaled on stakes, as was often the case. It was tough of Benedict to go in there at all.
Fifteenth-century Romania (Wallachia was part of Romania, as was Transylvania right next door) literally seems like Hell to me -- constant warfare, people getting tortured to death all over the place, government by sheer terror. Mircea, Vlad's older brother, was buried alive by their father's political opponents. Obviously the peasants didn't have much choice, but the fact that the noblemen and tradespeople didn't get the hell out of there and go almost anywhere else suggests to me that they and I just think about life very differently. I think of it as something to be preserved at almost any cost; they probably thought of it as something they were likely to lose next year anyway, so why not grab for the brass ring? Dying on a stake might not have been substantially worse than dying of measles.
Still, to walk into that room full of people on stakes? Not all of whom were dead? Even for the fifteenth century that must have been bad, and yet somehow Benedict de Boithor and people like him dealt with stuff like that over and over again because that was just how the game was played. Did every Eastern European nobleman have massive post-traumatic stress or what?