GCSE's

Why do we have to do GCSE's? It's practically a memory test which doesn't take any of your knowledge into consideration

I wouldn’t say they are just memory tests. And even if they were, good memory is very important. Exams are more about using your memory and applying it to a question. It would be wrong to call essay based exams like English and History memory tests as you use memory in conjunction with other skills to formulate a concise and logical response to the question.
Even in maths exams it is not a memory test you have to apply your memory into different questions to get the right answer.
I don’t think any GCSE exams are purely memory tests.

Also I don’t know why you are singalong our GCSE’s even in A Levels and further on memory plays an important role in your exam.

But I do agree that GCSE’s are pointless especially if you want to pursue higher education. They are basically only useful for getting into certain sixth forms/colleges and most universities don’t even care about your GCSE’s. The only use for GCSEs really is to prove that you have basic knowledge of maths and English so you can work basic jobs.