Job application: your greatest achievement 😓

I’m applying for several internship and vacation scheme positions. For the common interview question, “What is your greatest achievement?”, I want to talk about a BTEC assignment that helped me develop a strong commercial mindset. However, I want to avoid sounding cliché or like I’m just listing soft skills gained from coursework, as many candidates tend to do.

How can I frame my answer so that my commercial mindset is the achievement itself, with the BTEC project serving as evidence — rather than describing it as something I simply developed through the assignment?

Thanks