National Grouch Day is celebrated on October 15 to honor Oscar the Grouch from "Sesame Street." This day encourages people to embrace their inner grouch, allowing for complaints, irritability, and expressions of negative emotions. It serves as a reminder that processing these feelings can be beneficial. On social media, individuals commemorate the day by sharing jokes, memes, funny photos, and stories related to grouchiness. The observance highlights the fun side of being grouchy while promoting a lighthearted approach to negativity.