Do selfish students damage the chances of others?

For those undergraduates taking their finals, this is a stressful time of year. Three or Four years of study are coming to a conclusion and for many the extra hours of graft will make a difference between a 2:2 and a 2:1 or missing out on a 1st. It is clearly an advantage to finish exams early. Yes, you have less time to prepare but you are not hindered by late night post exam celebrations of others. For those still revising there is always a worry of getting a good nights sleep as your flatmates and/or neighbours return in the early hours still in the mood to party. Whatever the intention is to be considerate a few 'three for the price of one Web Lobbler's' later and the peaceful night's sleep is lost and maybe so is that grade you needed.