Then later on in the term there will be projects and workbooks and the endless paper trail of letters about everything from school rules to Nativity costumes. And you also have to manage the rest of your life – you know, things like food shopping and cleaning the house and having a wash and going every day to that 'job' thing that pays the bills.
But the main overriding concern for most mothers is that you must NOT forget anything. Write reminders on your eyeballs, buy a life planner, put post its on your forehead with backwards writing on them. Because if you're a mum and you forget something – a doctor's appointment, a nappy, suncream - it's easy to feel like a complete failure.
"I feel like a bad mother if I forget things," says mum of two, Victoria. "Particularly when society judges you for simply being human. Mothers are people, not robots."
We all know we're not robots, yet often women seem compelled to behave like The Mumbot3000 – always smiling, always giving, with unlimited memory capacity.
I have seen clever, funny, successful women reduced to nervous wrecks over a forgotten school tie or the wrong kind of Frube.
My fear of forgetting is turning me into a lunatic. You should have seen the sheer panic on my face when my child's teacher announced 'Wellie Wednesday'. His old ones didn't fit, so I dashed to Asda in a state of hysteria not seen since the opening scene of Cloverfield.
Of course, in the grand scheme of things these are trivial matters. It's not like we left our kids on the bus, or in a dirty nappy for days. But the fear is that if we forget something we will somehow be exposed for being neglectful.
"If I forget something, it just makes me feel so incompetent and as though everyone else must care about their children slightly more than I do.
"I know it's irrational but I always feel incredibly stupid.
"But then I get quietly enraged and want to shout at everyone about how many other things I have to remember and try to fit into my day. Which is also stupid, because everyone has a ton of stuff to remember. And I never learn from my mistakes - so on it goes!"
One catalyst for this sheer panic is fear of how others see you – namely Other Parents – who will occasionally (and not always unwittingly) destroy your parental self esteem by remembering everything with bells on.
Bringing mountains of lockable Tupperware out of their nappy bags filled with organic cucumber chopped up into perfect 3 inch sticks, while you open a packet of Wotsits. Dressing their kids for the rain in head to toe designer oilskins while you follow your damp toddler with a broken umbrella.
Knowing, by some magical telepathy, that the school needs old newspapers for school crafts, while you're stuck in traffic, hyperventilating about picking them up on time.
Yes, that can be infuriating, but why do the rest of us feel the need to play catch-up? Can't we just say 'Ooh, aren't you organised? Well done' and leave it at that? Why the constant desire to compare and contrast?
The women I spoke to had several theories. "There's a sense that as a mother, you're supposed to get things right," says Gail.
"We're hardwired to find something to feel guilty about," says Elinor.
"I think it's down to residual guilt about going to work," says Kate. 'My kids go to a small school where most mums stay at home and do the PTA. I feel like forgotten stuff highlights my failings, although I'm aware it's probably mostly my own construct. But I imagine thoughts of 'Oh she wants it all and now look what's happened'
"I think there's a really big pressure to be perfect and utterly child-centric yet sometimes life ain't like that."
Dads aren't immune to beating themselves up either. "When we go on trips I always forget things like hats, water and sun cream," says dad of two Shaun. "At work, I'm juggling all sorts of responsibilities and rarely mess up. So why am I a dunce with my precious ones?"
So what's the solution? Well, It would seem the more kids you have, the less time you have to get neurotic about forgetfulness – after all something has to give, and it might well be a stray water bottle or little Jimmy's special teddy bear.
"I used to worry about forgetting things, but now I'm pregnant with my third, I don't beat myself up as much about it. Life's too short," says Clare.
Plus, it's worth remembering that despite outward appearances, we're all bumbling along trying not to forget – even those mothers who appear to have everything sorted.
Jess, mother of twin girls, says: "People think I'm some kind of superwoman because I breastfeed twins. But if I had to go through the rigmarole of sterilising bottles, boiling kettles, faffing with formula, cooling bottles... then actually REMEMBERING to take the damn things out the fridge, we'd never get anywhere. Or starve. At least I can't forget my boobs." Indeed.
You can read more articles by Lucy Sweet here.