What does it mean when you say it's a big onion day?

When someone refers to it as a "big onion day," they typically mean that they are experiencing a range of emotions or challenges that may lead to crying or feeling overwhelmed. The phrase plays on the idea that peeling an onion often makes people cry, suggesting that the day may involve confronting difficult or layered issues. It can also imply a day filled with deep reflection or significant personal growth.