Matthew Ricks's poem is a small argument that the speaker seems to be losing. Someone has asked to be told when the speaker gets home safely, and the speaker pushes back: you know I drive carefully, so why does it matter? The question sounds a little annoyed, as if the request feels unnecessary or even slightly controlling.
But the poem's brevity leaves room to read it another way. Three short lines can't hide how much the request must mean to the other person. Driving safely isn't the same as being safe, since the road holds dangers no careful driver controls. The check-in isn't really about doubting the speaker's skill. It's about worry, and about wanting reassurance that someone you care about is okay.
The mood is quiet and a bit tense, caught between irritation and tenderness. The speaker's defensiveness may be the poem's most telling detail, because the question answers itself. The reason to need to know is simply that the person cares.