Depends on the universities policies. Sometimes they only want achieved grades within a certain time frame, so like if you sat exams in like 2019... universities normally say like if you sat exams from 2020 downwards (just an example) then you’ll not be considered. But this is rarely ever the case for non competitive courses. As long as you meet the requirements then you’ll be considered, and if you’re lucky, you’ll be offered an unconditional offer rather than conditional.
As for you not remembering content, it’s ideal to refresh yourself on content when you are about to go to university but it’s not always necessary.