The speaker of this short poem claims not to care when the world ends, and the reason is surprisingly calm: it has happened before, many times, and each time the next morning arrives anyway. The first lines sound almost like a shrug, helped along by the casual missing apostrophe in "dont." Nothing here is shouted or dramatized.
What the speaker feels seems to be a weary, steady kind of acceptance. "The world" could mean literal catastrophe, but the poem also suggests the smaller endings in a life: a breakup, a bad day, a lost job, a failed plan. Each one feels like everything collapsing, and each one is followed by morning. The final line, "And began again in the morning," carries a quiet hope without making a big promise.
The mood is deadpan, gentle, and a little consoling. It treats disaster as something survivable and even ordinary, and that makes the speaker's calm feel earned rather than careless.