Another possible reason for lack of concentration is that the task in front of you feels so enormous that you don’t know where to begin. A good way of combatting this problem is to break the task down into smaller, more manageable tasks. For example, rather than putting an entire essay on your agenda, divide up the tasks into smaller, more easily achievable goals: read a chapter of a book and make notes, write the essay plan, write the introduction, and so on. You could even break it down into numbers of words to be achieved: 100 words at a time, for example.