What will happen if my visa expired and I'm flying out of Thailand tomorrow?

The original poster is concerned about the consequences of their visa expiring four months prior, as they plan to fly to India the next day. Comments indicate that they will likely face a fine of up to 20,000 baht and a possible one-year re-entry ban when they attempt to leave Thailand. It is suggested that getting to the airport is crucial to avoid being detained. There is uncertainty about the exact penalties, but the community agrees on the likelihood of a fine based on their overstay.