I agree!
I have just completed all 14 and had been out of education for a while.
I planned my time carefully and did chunks at a time - say 1hr with a 10-15 mins off doing something completley different and then back to a different subject. I worked out a timetable and stuck to it.
Find what works for you and enjoy it!!!!
pm me if you need any more specific hints with the different subjects!!