Love can flourish only as long as it is free and spontaneous; it tends to be killed by the thought of duty. To say that it is your duty to love so-and-so is the surest way to cause you to hate him of her.
Death is nature's way of making things continually interesting. Death is the possibility of change. Every individual gets its allotted lifespan, its chance to try something new on the world. But time is called and the molecules which make up leaf and limb, heart and eye are disassembled and redistributed to other tenants.
Rhymes, meters, stanza forms, etc., are like servants. If the master is fair enough to win their affection and firm enough to command their respect, the result is an orderly happy household. If he is too tyrannical, they give notice; if he lacks authority, they become slovenly, impertinent, drunk and dishonest.