That video is amongst the tamest ones available on youtube (and there are many). They depict the stupidity of drivers, highlight driver inattention and generally show the results of poor driving skills mixed with speed, weather conditions and badly maintained vehicles.
Before my wife sat her driving test, I had her watch some of these videos, just to demonstrate how quickly things can go wrong and to always expect the unexpected. Our 18yo son will shortly begin his formal driver training and he will be watching them too.
Not all of the videos were made in Russia..there are quite a few from this country as well and whilst the driving styles are similar, the results are always the same!
My advice to those of you who are new to Bulgaria, keep your trips short and fairly local until you are comfy with the 'wrong' side of the road, get used to the quirky habits of the locals (both drivers and pedestrians) and you will settle in nicely.
Above all..think safe, drive safe and stay safe.