system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:If you go small enough, even a line drawn on a paper has depth. Does true 2d actually exist on our world?
gpt
If we're arguing semantics then from a pure math perspective 2D doesn't technically exist.

However it starts to reach a point where something gets so flat or narrow that it might as well be considered 2D for all intents and purposes. Graphene is a common example of this - a material which is one atom thick and is about as flat as it's possible to get in the real world.