Almost certainly you'll have to lie. Almost certainly, you'll have to pretend you're interested in seeing the culture, exploring the backstreets of the Old Quarter, or wandering around the former jail where Senator John McCain was once held. You'll have to gloss over the fact that what you're really all about, is getting stuck into what may be the world's cheapest beer.
In Vietnam you don't need to look too hard to find Bia Hoi, a light, pale, locally made lager that the locals wash down as if it were bottled water. At as little as 5,000 Dong a glass (about 18p), you'll find that money is not a barrier to immersing yourself thoroughly in this very Vietnamese pastime, especially in elegant Hanoi where it feels as if a bar selling this quaffable, not-overly-gassy brew, looms from every corner.
It may not be the most sophisticated pursuit. There are plenty of new shiny bars in Hanoi, the capital of a still-Communist country that has energetically embraced capitalism, but the establishments selling Bia Hoi are not among them. Rather you're more likely to find yourself in a large, rough-and-ready premises, often open to the elements and with the floors littered with casually discarded peanut shells. As you sit there in the late afternoon sun feeling a little reckless with it all, a waitress or waiter will keep tabs on how many beers you've drunk by marking scratches on your beer mat.
But this is a good thing. This is how you'll make friends. Forget about chatting with the seemingly friendly rickshaw driver as he stands on his pedals to haul you off to Ho Chi Minh's mausoleum; he's just interested in earning a fat tip. The people who will initially stare at you in the Bia Hoi bar before coming over to try and strike up a smiling conversation, might really be your new best friends. At least that's how it can feel after a few glasses. And why not buy them a round? After all, it's not even going to cost you more than a pound.
What's that about something to eat? Oh, the Bia Hoi bars all have kitchens out the back, places perhaps that you might do well not to scrutinise too closely, but you'll not go hungry. And the little plastic-covered menu cards – one or two conveniently translated into English – have everything any respectable drinker might want to snack on. One evening, the senses were overawed simply by thinking about the exotic array of dishes on offer at one scruffy establishment – roast dog, bull's penis, dog's penis, testicles, swan, frogs. Actually the frogs were pretty good; a bit crunchy because of the bones, but pretty good. I didn't bother with anything else. Even the most adventurous traveller knows where to draw the line.
As some point the joys of all this childlike abandon, this sad attempt to recreate your student days may start to pale, at least with your travelling companion. This is when you may feel the pressure to dive into some more traditional tourist activities. So do so. Get up at dawn and join the throngs of people exercising in unison around the still waters of Hoan Kiem Lake, go and take a look at John McCain's pilot's jumpsuit hanging behind glass at the so-called Hanoi Hilton, or jump on an overnight train to Sapa and wander the hills that are home to villages of the Black and Red Hmong tribes. If you really must, you can join the tourist hordes at Halong Bay, queuing up for boat-trips to get up close to the admittedly remarkable limestone karsts.
If you're clever, all of this can be built into your cover story. Go along with it, show enthusiasm even. There's no need to let on what's really driving you.
Here for the beer
* Go on a journey through the Czech Republic and see where some of the best beer in the world was first brewed and is still being made according to centuries-old recipes. Four-day tours from £399 pp. 01273 600030; responsibletravel.com
* Have a pint with the locals at Löwenbräukeller in Munich. This factory of a bierkeller is beautifully decorated both inside and out and beer, by British standards at least, is not bad value at just over £2 a half litre. 00 49 89 52 89 33
* The Sixtus Trappist abbey in Flanders, Belgium is said to produce some of the best beer in the world. It's hard to get hold of but is usually served up at Chez Moeder Lambic in the Elsene neighbourhood of Brussels. And if not, this old, tiny wooden tavern has a staggering range to choose from. 68 rue de la Savoie, 00 32 2 539 1419
* Byens Kro in Copenhagen may date back to 1783 when it was a distillery but the bar serves up beers both venerable and fashionable from Steam beer made by the West Coast brewery Anchor, to the house speciality Byens Øl brewed on the Baltic island of Bornholm especially for Byens Kro. Møntergade 8, DK 1116 K, 00 45 33 12 55 89