Drivers not aware of their surroundings?

Coming home from the office this afternoon. Local college and schools had turned out with a lot of students around. Car driver behind me was impatient due to me at times driving below the 30 mph limit because of the potential danger of students stepping out on to the road! Later whilst slowing to turn left at a very sharp turn at a traffic light controlled crossroads the same driver hooted his horn and stuck his finger up at me?  Totally confused by this bizarre behaviour?! However, I suspect the driver was not aware of the potential danger, has no perception of risk and may need to think about some advanced driver training to help him and other road users stay safe. Were you driving a silver Ford Fusion, wearing a woolly hat and about 50 years old? If it's you, phone me for some free training!