My mum and dad were in the pub trade and dad had a tradition of always buying his regulars their first drink on Christmas Day as a thank you for their custom over the year He was very much of the "old school" pub gaffer type which I think is sadly missing in the pub trade.
This fella come in one year and said he thought the free pint applied to everyone
Dad turfed him out and said he was as regular as haleys comet