In 2020, what number of countries and territories required a person to drive on the left side of the road?

Driving on the left is the original way. Because most people are right handed knights carried a jousting pole in that hand with their opponent on their right. Left hand drive. Also to defend yourself with your sword you wanted a would attacker to be on your right. Hence left hand drive. Apparently when Canada moved over to the other side of the road the trucks moved on Sunday and the cars on Tuesday😀

actually i can drive with both of my hands by left side and right side roads

There is a logical point. The side of the road was decided when people rode horses, and carriages/wagons... Universally, the near side of horse is the left: you always mount a horse left foot in the stirrup first (also true for bicycles). So approaching a horse from the near side, the horse in on the left. In American westerns, the cowboy will have to turn his horse 180° before going forward. Look for it next time.

Player #53553731, yes, left hand drive cars drive on the right side of the road. I have had this miscommunication with a Filipino before. Most people describe the side of the road that the car travels on. Not the side of the car the the steering wheel is on.

Funny that America went with Europe.

Also did not mention Japan.

Obviously the correct side of the road to drive on!!