Have you ever noticed that you can go on holiday for 2 weeks, drink all day, go out and get absolutely wasted in the night. And then get up the next day and do it all over again. You can do this for 14 days and not get a hangover, when you're on holiday. But you can go out on a Saturday night when you're at home and wake up on the Sunday morning with a massive hangover.
Why is this?