Avoiding declamatory dialogue, "Breakfast with Curtis" explains a lot about its characters through their actions. For example, at this point in his early life, Curtis is trapped in his gangly body. He's too old to not look awkward when he day-dreams. But he needs time to space out since he is, at first, a personality-less void. When he jostles around in bed, you get the sense that Curtis doesn't really think much of anything.
And when he plays the piano, he has prodigious muscle memory, and hits all the keys with admirable technique. But his playing isn't passionate, probably because Curtis is 14 years old. Enter Syd (Theo Green, in his tremendous debut), the book-selling raconteur and layabout next-door. Syd asks Curtis to help him film some YouTube videos of wherein he rambles about all and sundry: the weather, his favorite bar, memories of great books, and greater people.