>>>and it seemed fairly easy
Driving a car round a car park is easy. A bit like driving round a dodgems at a fun fair, any person can do it, even a child.
But proper driving is much more than that.
Making sure your speed is right for the road, dealing with traffic lights, roundabouts, zebra crossings, t junctions, hills, bends etc.
Watching other road users, knowing all the various street signs, knowing how long a car takes to stop in an emergency, dealing with rain and snow and ice, using your mirror.
Also overtaking and when to overtake, doing a "three point turn", doing a "hill start", motorway driving, knowing when it is safe to pull out of a side road and so on and so on.
Lots to learn.