Prelims are still in place this year but this is the last year they'll have them. Prelim grades don't really matter, the total amount of studying I did last year probably amounted to less than 10 hours, I did pretty poor in my prelims but went on to get perfect exam results. I've always been fortunate in that I'm chilled out during exams, I actually find them quite fun strangely
My PTTGOYN for today is Higher Physics. Some of it is absolute mindfuck material at first.