In "A Defence of Poetry,” Shelley suggests that emotions experienced in life are constantly changing. The following lines from "Mutability” can also be seen as a reflection of this idea:
We feel, conceive or reason, laugh or weep;
Embrace fond woe, or cast our cares away
This lines are saying that our emotions change, laugh reflects joy while weeping reflects sadness. Also, one can hold on to woes (sufferings) or one can let go of those. This lines are expressing different emotions one has and therefore reflects the idea that emotions are constantly changing throughout life.
Answer: Following instructions are important because if you don't follow them like you're supposed to, in larger settings, it can cause chaos. Rules are put in place to avoid that.
The first sentence gives the main idea of the selection
<span>Examples, facts, statistics, and description may be used to support an author's claim. </span>