Having lived in Japan and rented cars in England and New Zealand, I have driven on the left side of the road before. True, I occasionally turn on the windshield wipers to signal a turn, but as long as I repeat the mantra, "Keep to the left. keep to the left!" I am, generally speaking, OK. Nervous, but OK.
But driving in Thailand is a bit more challenging, especially in rural Thailand and even more so at night. For one thing, two-lane roads seem to be more than two lanes. It is normal and acceptable for people to pass down the middle. It's simple really. The person being passed moves over and the oncoming driver does too. This creates a sort of a third lane down the middle. A grateful driver may flash their lights in appreciation. (Nobody in Thailand ever honks their horn.) The shoulder-less roads have reflector marker posts on each side at just the right height so they look just like the reflectors on vehicles themselves. It starts to get a bit confusing and, on mountain curves, your hair begins to stand on the back of your neck.
Huge, double-decker tourist buses on the all-night drive from Bangkok seem to have the understood right-of-way. They plow down the middle of the road with impunity. For some reason they do not use their headlights at night. Wide-eyed long-haul bus drivers, who frequently sniff at benzedrine inhalers to stay awake, peer into the moonlight at 70 miles per hour even in the towns. If they have an accident, they may just jump out of the bus and run into the jungle to avoid prosecution.
After driving for a while, you might begin to relax a bit and get used to it all. You convince yourself there seems to be plenty of room on the road, except that now there are also small extra added lanes on the outside of both auto lanes to accommodate the sudden horde of motorcycles. It starts to get a bit crowded and chaotic. Add to this the fact that the motorcycles and scooters usually have one to three passengers, including babes in arms, and that some of the motorcycles have side-cars stacked high with various goods and produce.
In some areas, great numbers of pedestrians use the motorcycle lanes as well. On their way to town for the evening or home after work, frequently clad in dark clothing and walking two abreast holding hands (both men and women), they casually step aside, if necessary, off the road slightly. They don't seem to be concerned at all as their clothes flap in the breeze of passing vehicles.
Packs of street dogs bark and snap at your wheels as you pass. Roosters chase hens and stop to peck at flattened snakes and lizards. In a final note, add the occasional elephant, almost invisible in dark grey, but with battery-operated running lights hanging from forehead and butt, strolling home after a hard day of work in the teak forests.
White knuckled, butt puckered, you hope the Buddha is watching over you.