By far the most common difficulty in study is simple failure to get down to regular concentrated work . This difficulty is much greater for those who do not work to a plan and have no regular routine of study . Many students muddle along , doing a bit of this subject or that , as the mood takes them , or letting their set work pile up until the last possible moment . Few students work to a set timetable . They say that if they did work out a timetable for themselves they would not keep to it , or would have to change it frequently , since they can never predict from one day to the next what their activities will be . No doubt some students take much more kindly to a regular routine than others . There are many who shy away from a self-controlled weekly timetable , and dislike being tied down to a fixed program of work . Many able students state that they work in cycles . When they become interested in a topic they work on it attentively for three or four days at a time . On other days they avoid work completely . It has to be admitted that we do not fully understand the motivation to work . Most people over 25 years of age have become used to a work routine , and the majority of really productive workers set aside regular hours for the more important areas of their work . The " tough-minded " school of workers doesn't fully accept the idea that good work can only be done naturally , under the influence of inspiration  . Those who believe that they need only work and study  _ have a mistaken belief either in their own talent or in the value of " freedom " . Freedom from control and discipline leads to unhappiness rather than to " self-expression " or " personality development " . Our society insists on regular habits , timekeeping and punctuality ( being on time ) , and whether we like it or not , if we mean to make our way in society , we have to meet its demands . The most widespread problem in applying oneself to study is   _   .
changing from one subject to another the failure to keep to a set timetable of work the unwillingness to work out a systematic plan working on a subject only when one feels like it