(broken down in several posts as this grew too long)
1. Food: oh my God, the food. I might be a tourist and more than a little lost in Vietnam, but the food is always like coming home (and it’s no coincidence that the one place I’m never lost in is restaurants). Plus, you always eat well at Grandma’s house (thanks to the combined efforts of Grandma, my maternal aunt, and my cousin). We also tested and patented the food crawl as we were travelling: this is a technique by which you get up at 6:00, have a cup of tea, eat a breakfast soup at 9:00, have lunch at 11:00, then have a boat ride on the Mekong and have a copious snack at 15:00, and proceed to dinner at 17:00 (all the while being pointed to food in various peremptory ways, and being told to eat in either French or Vietnamese). That’s discounting special events where you are well and properly stuffed, banquet-style (our stay intersected my great-grandmother’s death anniversary, and a two-year death anniversary for my great-uncle, which is basically when the period of mourning ends for the descendants); and it explains why we came back from Vietnam sated, but determined to undergo a diet of salads. 
2. Orientation: Grandma very sensibly wrote the address of the house on a bit of paper (well, OK. First she told me to repeat it out loud, then she grimaced and said she was going to give me a bit of paper… Remember what I said about my pronunciation sucking?), and that was what we gave taxis as we zoomed around Saigon. It puzzled them no end that two very obvious tourists (one White guy, and one vaguely Vietnamese-looking gal who obviously couldn’t speak very well) would ask to be dropped in what seemed to them the back end of nowhere. Mostly it was fine, but we did have one taxi driver who kept circling the house, looking for a hotel where we could be staying… (when this was explained to Grandma, she laughed very hard and said she was the cheap variety of hotel). In the end, I gave up the pronunciation game–it’s just too frustrating to argue with a cab while the meter is running–and copied down street names on a bit of paper. (I think the only two places that I said out loud that didn’t suffer from a pronunciation problem were the Bến Thành market, which is a touristy destination, and the word “crossroads”, but it was accompanied by a list of two street names, and a rather graphic gesture of a cross made with my hands).
3. Tourists vs. locals: the H and I spent a most profitable afternoon in Hội An  observing an ever-increasing flow of local tourists vs Westerners, and we’ve come to the conclusion that the one difference between the “locals” and the Westerners is–guess who’s wearing the T-shirts and shorts and getting sunburnt? (getting dark skin is considered a bad thing in Vietnam, so a lot of people dress with long-sleeved shirts, trousers, and sometimes even gloves and facemasks. And I shudder for the poor kids decked out in thick winter clothes, because it’s colder in the Centre, but most certainly not *that* cold).
 I didn’t escape the ritual bout of food poisoning in Hội An–two days out, and I basically couldn’t keep anything down. Thankfully it didn’t last long, because it was a bit stressful to be rushing about in a temple complex trying to explain with gestures that I was going to be sick and needed to get away from the sanctuaries before it got messy. Also, explaining in a restaurant that I was sick and needed cháo (rice porridge) was worth a laugh or two (I mangled the pronunciation completely, but enough of it got across that I basically got a custom dish made up for me).
 Incidentally, if anyone knows of a festival that happens to fall on Feb 8th/the 17th day of the First Lunar Month, we’d be interested. We were mildly curious at the queue of pilgrims outside the Quan Vũ/Guan Yu temple in Hội An, and we couldn’t figure out why they’d be there (I know Guan Yu’s death anniversary is on the 13th day of the First Lunar month or something, but the date doesn’t coincide).