O level is easy if you prepared yourself well. I prepared myself
by doing TYS over and over again.
You're considered fully prepared when you reached the stardard of
being a teacher yourself. It's because you fully understand the
subject and are able to teach other people.
This is how I do well for my Science.
Having Passion in the subjects will also have great help. If you
like something, you'll do well in that area generally.
5(L1R4) or 6(L1R5) marks means all subjects getting A1.
There are people getting less than 5 or 6 points because they have
CCA to deduct.