What is it about Irish people leaving gigs in big groups that makes for such mighty craic?

We've seen the below scenario play out numerous times over the years; people are waiting to leave a big outdoor venue via a certain exit. Some poor unsuspecting person is tasked with the job of making the announcement/giving directions over the tannoy. Crowd cheer and boo at random intervals, etc.

That's exactly what happened as the crowd were leaving Slane the other night after watching Guns N' Roses et al. Given their cheering for the red exit (yayyy) and booing for the blue (boooo), you suspect a drink might have been taken by many of them - but at least the announcer had a sense of humour about the whole thing.

Ah, sure, aren't we great altogether, lads. *pats self on back*