Do Not Go Gentile Into That Good Night

Do Not Go Gentle into That Good Night Summary
The speaker asserts that old men at the ends of their lives should resist death as strongly as they can. In fact, they should only leave this world kicking and screaming, furious that they have to die at all. At the end of the poem, we discover that the speaker has a personal stake in this issue: his own father is dying.
Lines 1-3
Do not go gentle into that good night,
Old age should burn and rave at close of day;
Rage, rage against the dying of the light.
The speaker addresses an unknown listener, telling him not to "go gentle into that good night."
At first this is a puzzling metaphor but, by the end of line 3, we realize that the speaker is using night as a metaphor for death: the span of one day could represent a man's lifetime, which makes the sunset his approaching demise.
"That good night" is renamed at the end of line 2 as the "close of day," and at the end of line 3 as "the dying of the light." It's probably not an accident that the metaphor fordeath keeps getting repeated at the end of the lines, either. Or that the two rhyming words that begin the poem are "night" and "day."
So what does the speaker want to tell us about death? Well, he thinks that old men shouldn't die peacefully or just slip easily away from this life. Instead, they should "burn and rave," struggling with a fiery intensity.
The word "rave" in line 2 connects with the repeated "rage" at the beginning of line 3, uniting anger, power, madness, and frustration in a whirlwind of emotion. Oh, yeah, it's going to be one of those poems. Get ready to feel.