Symbol Analysis
Ah, to be lazy all day, without a care in the world. The speaker praises laziness (hence the title of the poem) and prefers its sedation to any other pursuit. As a result, sleepy, idle imagery is sprinkled throughout the poem.
In the second stanza, the effects of a relaxing day "numb" his eyes, slow his pulse, and remove his pain. "Ripe was the drowsy hour" he says, in line 16, using a simile to compare a lazy time of day to the ripeness of a delicious piece of fruit.
Plenty of "sleepy" imagery reappears in stanza four, where the speaker praises "drowsy noons" and lazy evenings. "O, for an age so shelter'd from annoy" he continues in line 38. Here, the speaker wishes he could just avoid the annoyances of daily life altogether.
And that's how the poem ends: with the speaker leaning back into the grass, enjoying an lazy day that will no longer be interrupted by ambition, love, or the urge to write poetry. All of those require effort and are pretty intense. The speaker prefers to stay idle and numb.