Depends on how fast you're drinking. At a wedding you're drinking more slowly, whareas if you go out on the piss you're drinking much faster. I guess the aul liver can only break down the alcohol at a certain rate.

Anyway - guaranteed hangover cure. Water. Drink a pint of it between every two/three pints and then knock a pint of it back just before you go to bed. You're still get pissed and do a lot of pissing, but you'll be headache free in the morning