Four short lines, and a whole mood of wounded pride. The speaker lists two small details about their appearance: white teeth and a blue collar. Everything looks fine, even tidy. Then comes the complaint: "You forgot to feed me." The poem ends with a blunt conclusion, "So I hate you."
Who is speaking isn't stated, which makes the poem interesting. The neat teeth and collar could suggest a pet wearing a collar, or a child, or someone who simply keeps up appearances while feeling neglected. The poem doesn't settle it, so you can read it more than one way.
The feeling is simple and raw. The speaker moves from hunger to hatred in a single step, with no pause for explanation, much like a sulking child. That gives the poem a tone that is both funny and a little sad. The rhyme of "blue" and "you," and the title's "No1UCareAbout," hint that the speaker feels unnoticed, and the hatred may really be hurt.