To drop an at-om bomb at midnight, to put all wisdom down in writing, to become a university wit, perchance to gain a morsel of underground knowledge and realise that the mistaken belief about an owl’s call being “twit twoo” derives from Shakespeare – ay, there’s the post-pub grub, and in it I will slip a coiled-up myth that acts as an acasual connecting principle between twitterers on opposite sides of the Globe.