NC for this as I'm a little embarrassed. 
To clarify: I'm not planning to become one of those eccentric 'leave them up all year' people (far too much dusting for starters!) No, but I'm thinking of leaving the decs up till later in January, possibly the end of the month. No, I'm not crazy. I'm always a little sad when the decorations come down, but this year I've realised properly for the first time why that is. It's not just my inner little kid coming out to play (although that too, lol); it's that while the decorations are up, they really help my SAD (which tends to kick my butt HARD for much of the winter) to an astonishing degree. It's not just the lights (although those are helping keep my spirits up no end), but the general festivity of Christmas decorations (and, at the moment, the wonderful smell our real tree is giving off, that's a real mood-lifter).
In a nutshell, I'm just not ready to let my festive mood go out the door along with Twelfth Night when it's helping so much with my SAD. I feel like this every year and I always thought I was just being a child. I partly am, I know that , but I'm also in a 'WTF!' mood about it this year, having realised how much the decs have been boosting my normally flat and vaguely depressed winter mood.
DH thinks I'm mad but doesn't actually mind, and my elderly mother who lives with us also has SAD and feels the same way as me about the decorations providing a 'lift'. So I'm giving serious thought to:
- Leaving the tree up until it's shedding too many needles to be worth keeping up any more (dunno how long that will be for a cut tree, we've always been diligent and taken them down on 12th night) and just enjoying it to the full while it's alive. (Tree is in our conservatory at the back of the house, so there's no one to see from the street and think we're barmy.)
- Continuing to switch on the fairy lights we have strung up around the conservatory and in the porch, and keeping the two strings of lights we have outside on the fence going on their timer setting until the batteries conk out (and possibly beyond, because I find them so cheering).
- Keeping the rather wonderful winter display I've created on a chest of drawers in the hall, and just removing a couple of the more overtly Christmassy items.
Hoping that by the time everything finally does have to come down, the longer days will have kicked in and my SAD won't lie as heavily on me any more, that usually tends to be the pattern.
I've got to be honest, the more I think of doing this, the more I want to just say 'sod it' and do it. AIBU? (and I'm quite prepared to be told I'm a whack job, BTW.)