Need help. I got a pfl stating that I misrepresented myself by not declaring a study permit refusal while applying under canadian experience class PR application. I genuinely forgot about it. I had a refusal on nov 3,2016 which was followed by a approval on dec 30,2016 and i landed in canada after a week. But i have declared this refusal in my second study permit application. After my studies got finished i got a work permit on the border and never the officer had asked me about any refusals so this refusal never crossed my mind after i came to canada. I donot get any points or credits by hiding this refusal. It was a honest mistake. I was too overwhelmed after getting ITA i honestly forgot about the refusal. How do i convince the officer. Pls help