This manoeuver is designed to teach you how to stop your car safely as quickly as possible. If a child runs out in front of your car, you don't want to be skidding and sliding all over the road.
This manoeuvre is one you'll use frequently as a driver. Reversing into a parking bay at a supermarket or in a car park is a key skill, and learning to do it right will spare you a lifetime of people making jokes about your driving.
An essential everyday skill which every driver needs to master in order to park safely on the road. A classic sign of an inexperienced or poor driver is the inability to park properly but assuming you can follow our basic instructions you'll never need to book a taxi to the curb again.
Your dad will probably call this a "three point turn" but luckily for passing your test you don't actually need to be able to do it in three. If you find yourself going the wrong way down a cul-de-sac then learning this simple manoeuvre will certainly save your blushes.
Reversing around a corner to the left can be used as an alternative to doing a "three point turn" where the road is too narrow or overly busy, and is a key skill to learn in preparation for your driving test.