It’s the period during which human activity had been the dominant influence on the climate and the environment. Which is causing animal extinction, habitat loss, global warming and chemical composition of the atmosphere. It’s also known as Anthropogenic Climate Change.
We are living in the Anthropocene Epoch which is characterized by humans domination over all other species on the planet. We are at the top of the food chain basically.
An implicit message is something that is hinted at but not directly stated by the speaker. In this case the phrase "I don't expect you to know what cool people wear" implies that the person being spoken to is not cool.
