Honestly, it depends on the way you've written it - nothing can really be 100% original if you think about it. My creative isn't the same as yours, but it has a similar theme: resignation to obligation. It's about a sick father dying of cancer, which is definitely nothing new, but I got 14/15 for it and the mark I lost had nothing to do with it being cliched. However, I was also very conscious of falling into a cliche, so I included motifs of birds and a piano to add some nuance to the story, extending it beyond the cliche. I also deviated away from the typical emancipatory experience - the persona never experiences any transcendence and is basically left in a state of existential paralysis at the end. So, adding slight adjustments like these, should be taken into consideration if you're really worried about the cliched aspects! My teacher - who taught a student who recently came first in the state for English Adv - actually promotes writing creatives that you have personally experienced so that the creative flourishes on an authentic voice. I literally read an exemplar about someone cooking which got 15, so don't think that the idea has to be extraordinarily unique or anything in order to reach the top band - it really is up to how you execute your ideas, ultimately!!