I'm with the OP. I work part time with a lot of flexibility and it is still difficult to keep up with. DH works full time and is about as much use as a chocolate tea pot when it comes to this stuff anyway.
Our school is very demanding with this kind of thing and I have one in Yr 2 and one in Reception . . . so far I've managed not to drop the ball anywhere, but I do feel like I'm flying by the seat of my pants most days! December is the worst with charity days, christmas plays, church service's, choir performances . . . add to that the usual birthday parties, after school clubs, reading, homework and you've got yourself an organisational nightmare!
You can choose to ignore certain things. I have gotten a bit better at that with things that I think the kids really don't notice, but some things I'd feel way too guilty about missing. Like if there's an afternoon for parents to come in to share a book or whatever, I'd hate to think of her being one of the few who's mum doesn't come.
My eldest has also been on at me since Reception to come in and be a parent helper. I couldn't in Reception because my DBS hadn't cleared, and Yr 1 I was mostly having a horrendous pregnancy with DC3, so I'm trying to add that into the mix this year too :/ Oh and then they both want me to come in for lunch too and I can't even do both at the same time, because Reception and Yr 2 eat at different times!
My mum worked full time when I was growing up and I do remember feeling sad that my mum never came in for lunch or picked me up like the other mums did. And there was one horrific forgetting of a dressing up day incident that sticks in my mind! I know a lot of kids probably wouldn't be bothered but since I remember my own sadness it makes me determined not to let mine feel the same. We're all shaped by our own experiences I guess.
A calendar is essential OP. Make sure you get everything on there as soon as the e-mail comes through and check it daily. And try to get things done as soon as you can. I.e. Sort the costume as soon as you know about it rather than waiting till a couple of days before!
One more week to go then we're home free for a couple of weeks! Phew!!