The manoeuvres arent even that hard tbh. They test more for control of the the car and observation than actually doing it well. You can even put it into 1st, go forward and straighten up and still pass it fine. If you're nervous you tend to overthink everything, meaning you react far slower.
In mine, the examiner asked me what I wanted to do in the future, to which I said I wanted to be a Pilot in the RAF (not anymore btw). That was like within the first 5 minutes of the test. Straight after that, did a parallel park, then straight after that the independent driving, which only took me into around 15/20 minutes of the test, after which the examiner said: 'I was in the RAF for 15 years.' Then just spoke to me about that saying it was the best career choice ever for the rest of the test. Dont even think he looked at my driving after the first 15 minutes!