The 'Reply Guy' meme characterizes a specific type of social media user known for offering unsolicited, condescending, or pedantic responses to posts, often targeting women or experts. While the term gained mainstream traction on Twitter around 2018, the concept roots back to various 'Well, Actually' tropes and the 'Mansplaining' phenomenon. The meme usually highlights the annoying habit of strangers inserting themselves into conversations to show off their supposed intelligence or to correct minor, irrelevant details. It is widely used to mock digital over-familiarity and the performative nature of online arguments, making it a staple for anyone navigating the nuances of modern internet etiquette.