Who's the blind stupid now?

Despite living in a family where people coo at him, "Li Po, are you a stupid dog? You're a stupid dog, yeah?" the way most people would coo, "Li P you're a cutie pie"; and despite being laughed at by the same family because he's going blind and bumps into walls when he walks up the hallway, THIS happened:

Yesterday my mom, Li Po's designated feeder and therefore recipient of his canine loyalty, came home from work late. So my brother, who wants very badly to be the recipient of canine loyalty, fed him instead. In the past, when my brother did this he wouldn't tell my mom and Li Po would luck out and get two dinners. So yesterday, after feeding Li Po, my brother left a note in the dog dish that read:

I fed the dog already.
--Brian

My mom came home, and in true robot form, promptly dumped a serving of dog food into the dish.

Li Po inhaled it.

Didn't you see the note?! Brian exclaimed when he found out.

Oh, no, Mom replied. I didn't have my glasses on.