1. Say "Christmas has really crept up on me this year!" at least once a day during December.
2. No longer describe mulled wine as 'rank hot Ribena' but 'delicious' and 'the only alcohol I can drink that doesn't make the room spin.'
3. Harp on about how brilliant It's a Wonderful Life is, like nobody else has ever watched it before.
4. Announce that you're off to do some wrapping and ask somebody to come and beatbox for you. Argue that making that joke is evidence that you are definitely still young and cool.
5. Forget to open your advent calendar for a week and eat a bar's worth of chocolate in one go.
6. Ensure at least 50 per cent of the items on your Christmas list can be described as 'sensible'. (Mine consists of tights, an umbrella small enough to fit in a handbag, and high quality pyjamas.)
7. Request kitchen utensils as stocking fillers. Pulling that garlic press you've always wanted out of a big woolly sock is the best way to kick off Christmas morning.
8. Be the one to suggest going for a walk in the afternoon on Christmas day. Detail the benefits of fresh air to those who protest.
9. Express concern that the feeling of 'Christmassy' now doesn't hit you until mid-December, if at all.
10. Sleep as well on Christmas Eve as you do any other night of the year. (Or possibly better if you've been to the pub for a festive pint.)
11. Start criticising the Christmas television schedule before it's even been published; make jokes about looking forward to seeing Chicken Run "for the umpteenth time!"
12. Admit that one of the best things about Christmas is that it gives you two days off having to interact with the general public.
13. Share the same Christmas anecdote you tell every year and watch your family tolerate it out of traditional politeness. (For example, mine is about Christmas Day 1988 when I was distraught that my Dad wouldn't let me ride my new bike in the house. I know, SO unreasonable.)
14. Avoid the topic of New Year's Eve until at least 28th December. Hope you can get away with just spending the evening indoors eating brie.