6. The honeymoon
At one time, people never freely married one another, at all. Grooms usually abducted their brides and disappeared with them. Over time, as people began to marry of their own will, they still considered the abduction method fun enough to turn into a ritual.
Right after every wedding, the bride and groom would go into seclusion as if the groom had just abducted his bride. They would stay there undisturbed, subsisting on the honey wine that their relatives brought them. Drinking honey wine for one moon (or 30 days) as they did, the entire ritual came to be called the honeymoon.