The beer was just as cold at Dice Bar, a lively corner dive with worn leather booths and a homey atmosphere. I got a thick pint of D’Arcy’s Dublin Stout for 4.80 euros. A couple of new friends I made, Josh and Keith, took me to Grogan’s Castle Lounge, where we found a freewheeling gathering; we caroused and drank in the street with about a hundred other people. After a crawl that also included The Bar With No Name and Garage Bar, we collapsed at a table at Zaytoon, a busy late-night Iranian restaurant that’s something of a Holy Grail for Dublin barhoppers.