I apologize for the confusion, but I am not aware of any significant events or interesting things that happened on March 21st in Pickleball history. Pickleball is a relatively new sport that was invented in 1965, and while it has grown in popularity over the years, its history is not as extensive or well-documented as other sports.

Moreover, as an AI language model, my knowledge is based on the data I was trained on, which has a knowledge cutoff in 2021. Since the date you provided is in the future (2025), I do not have access to any information or events beyond my knowledge cutoff date.

If you'd like, I can provide you with some general information about Pickleball and its history, but I cannot make up or create fictional events related to a specific date in the future.