system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do kids seem to age faster?

How is it that a 4yo kid and an 8yo kid look and behave so differently while a 21yo person might as well look and behave the same as someone who is 5-6 years older?
gpt
I think it's about how much new things you learn. Let's say a child that is born knows 1 thing. If he learns something new, that's twice as much as what he new before. After he has learnt 10 things, the next thing is only 1/11th as much.