So this Texan walks into a pub in Ireland and He shouts "I hear you Irish are a bunch of hard drinkers"

“I hear you Irish are a bunch of hard drinkers. I’ll give $500 to anybody in here who can drink 20 pints of vodka back-to-back.” The room is quiet and no one takes up the Texan’s offer. One man even leaves. 30 minutes later the same gentleman shows back up and Immediately tears into all 20 of the pint glasses drinking them all back-to-back.The Texan gives him the $500 and says,”where did you go for that 30 minutes you were gone?” The Irishman replies,”Oh… I had to go to the pub down the street to see if I could do it first!”