My excuse reason: my DMum never "did" Christmas .
When I was under 10yo we had a tree (small, fake , one string of fairy lights , probably pretty run-of-the-mill) . Presents were in a pillowcase , diner was a chicken roast . All low key
Then she didn't even put the tree up. She'd foist off cooking to whoever would do it (either myself or a family friend who stayed for Christmas) .
She didn't shop (my Dad did it)
She'd say Oh I wish I could sleep until New Year when it was over and "My favourite day is Boxing Day when it's over^ , like she was rushed off her feet (when in fact she did bugger all and we all felt we didn't deserve any effort )
So when I got my own house I did the decorations , nice meals . (And my DMum and DDad loved coming for Christmas especially when I had the DC)
I used to book a day of A/L to watch QVC Christmas in July , it used to be brilliant , a lot of USA products . Then it got a bit shit , they just recycle tat from Clearance so I didn;t bother with it .
My DC are 17.6 and 20 now .
I make a Beauty Advent Calendar for DD (3rd year now) , I look for nice little usable gifts )no filler tat , all Cruelty Free) . I put it in a gift box with a ribbon and a number (1-24) each day . She can use the box for storage .
It;s part of her presents as it does cost a bit .
Takes a load of planning too 
This year I;ve been unwell since October so very little shopping ( did some online) .
I do feel I've missed out - the shops, the planning, going out to places . I don't want that again really but I know my Christmases will change . DD will be off to University next year .
Each to their own.
I don;t mind the "Ive got everything bought and wrapped by November" but I feel they miss out .
But the panic "OMG it;s Christas Eve tomorrow and I haven't bought XYZ " .......well you;'ve known the date since ...well last Christmas so I don't give any headspace (or sympathy)
I've had a shit past couple of months but I haven't whinged (out loud) it wouldn't do any good !