I had to do the same thing: I spent ages crafting my ‘story’ of how my entrepreneurial experience translated to an interest in commercial law. After my first scheme, no matter how many times I tried to tag that experience to my answer, it felt out of place. In the end I started over; I took a blank piece of paper and wrote an answer to ‘why commercial law’ without referring to my original.
Even though it was frustrating having to scrap the original, the revised answer was much better. It was genuine and informed by my actual experience in the vacation scheme. So that’s my advice, start fresh, forget about your old applications and write down three bullet points on why you’re interested in corporate law. You’ll likely come up with an answer based on your vacation scheme experience.