The passage that shows how Kim uses time to emphasize his message is:
"But in truth, I wanted to participate. I wanted to run up to Timmy like a crazy person and yell, “YOU’RE IT!” I just didn’t know how."
This passage reflects a moment of realization and desire from the past, emphasizing the struggle Kim faced in his interactions and feelings around his identity. The contrast between his current feelings and his past desires highlights the passage of time and how it shaped his experiences and perceptions.