The truth is that when we are forced to do something we are unwilling to do that. What does it mean? It simply means that we do not like to do anything that is obligatory. If something is obligatory than everyone has to do it and thus we dont see the point of doing whatever it is that we have to do. We would rather decide on our own what kind o activity should we undertake and what has to be done in order to achieve it. Still our world works in such way that we simply has to do some things and we are not likely to change that. Fact is that our results are worse when we work under pressure. And when something is a must it always comes along with a pressure. Let us take free theory test as an example. Usually people have no bigger problems with passing this test and most of the time all of them pass it with nice result. Still sometimes there are some exceptions. I have seen few people who had terrible problems with finishing theory test with positive result. I was wondering why it is so hard to them. As it occurred later they simply had to pass it. Their future job depended on it or sometimes even the whole family. That made them really nervous and unable to pass theory test. Remember - when you work under stress your results will be worst than when you are relaxed.