OP here. By constancy of purpose I meant a more or less stable set of habits or processes, not goals. I agree big goals are difficult to achieve because as von

OP here. By constancy of purpose I meant a more or less stable set of habits or processes, not goals. I agree big goals are difficult to achieve because as von Moltke said, "no plan survives contact with the enemy". They can also be limiting, as you pointed out, because your interests may change.