The paper picks up from the widespread use by politicians and some educational theorists of maximising (including optimising) notions about those being educated such as 'reach their full potential' or 'make the best of themselves' or 'develop their talents to the full'. The paper discusses then puts some of these ideas on one side to focus on the injunction that school students should be encouraged to do their best. It puts forward a number of objections to this injunction as well as answers to possible counter-arguments. Its final two main sections discuss links with maximising ideas in moral theory, especially utilitarianism; and Michael Slote's case for satisficing rather than maximising as a guide to personal flourishing.