The major problem is - all the time you learn, there is an experienced driver sitting there stopping you from getting into bad habbits.
The day you pass your test, that 'filter' is removed.
So a lot of people get into seriously bad driving methods, but they never know they have because no-one ever tells them, so they blythly assume they are as good as the day they passed.
Human nature dictates that everyone else hooting and flashing just means they are the bad drivers!