The "does he know" meme is a humorous reaction meme that originated from a YouTube thumbnail created by the channel New Rockstars. It features the character The Riddler, portrayed by Paul Dano in the 2022 Batman movie, with the caption "Does he know?" in bold yellow text. The meme is typically used on social media to question or doubt whether someone (usually the original poster of a comment or post) has knowledge about a particular subject, implying that they might be unaware or not fully informed while others presumably do know. It gained popularity on platforms like Tumblr and Twitter in 2022 and has also inspired various remakes and modifications with similar humorous intent.

In essence, the meme serves as a playful way to question someone's understanding or awareness in an online conversation.