What happens if I don't receive my Non-O visa before my flight to Thailand?

The user inquired about entering Thailand if their Non-O visa (retirement visa) application is not processed in time by their flight date. According to the community responses, if the visa is not obtained before traveling, the user can enter Thailand as a tourist if they qualify for visa-exempt entry. However, once the Non-O visa is approved, they will need to exit Thailand and re-enter to activate the new visa.