Really shouldn't have got drunk last night but it was Jill's birthday. And I knew the headaches which awaited today, with hordes of excited seven to nine-year-olds on a coach for an hour and then on the rampage. So drank. Inevitable.
After last year's trip - train to London, on the tube, and to the Science museum - found myself waking in a cold sweat counting imaginary heads every night for a month.
Gallows humour permeating staffroom: those who are going on trip have that frazzled expression. Those who aren't are having a lovely time taking the mickey.
Still, one bright spot on the horizon: Luke Smoulder's class are off visiting their secondary schools today, so he's coming along (devastating in jeans and linen shirt) to give us a bit of backup.
Since he's been the subject of great speculation all this term - perfectly friendly and chatty, but not exactly forthcoming - this might be the perfect opportunity to find out more.
Like, does he have a girlfriend?
9.30am: Load everyone on to the coaches smoothly, and utter a little prayer to the God of Motion Sickness as we pull out of the gates.
9.32am: The first rustle of crisp packets as packed lunches are raided. Feel queasy myself as a tidal wave of Cheese 'n' Onion permeates the bus.
Sternly take my mind off this by delivering a swift talk on the significance of what we are going to see today (few rooms of stately home, followed by rare breeds sanctuary in the grounds) in the full knowledge that the gift shop and picnic are the high points on the kids' horizons.
9.55am: We are definitely on a school trip. Emily has just thrown up into the hood of Laura's coat. Notice Luke watching as I expertly transfer detritus into carrier bag and pick odd bits out of hair.
10.15am: Joy - arrive at Posh Hall without any further sick incidents. Must be a record. Hand out clipboards and questionnaires, ferry kids off bus with Luke - Mr Smoulder - bringing up the rear. Check bus. Find 15 lunchboxes and 17 coats.
As expected, Posh Hall amazes pupils, who don't seem to get dragged round these places quite like I did as a kid. They're a bit puzzled by the rope until we explain it wouldn't have been there when the room was in use. "Where's the telly?" Darren wants to know.
Am mentally congratulating myself on smooth running of visit after uneventful 10-minute walk to rare pigs. Lee pipes up slowly: "Miss Chalke. You know that house? That house we've just been in? I left my bag in it."
Luke goes up several notches in my estimation when he offers to go back for it.
Lunch at 11.30: ( another record) and kids don't seem to mind persistent drizzle. They want to find the shop, but get them into the farm instead. Manage to sidestep extremely awkward question about the donkey. Spot Luke smothering grin.
1.30pm: Starts pouring, so head for the shop. A very important part of the trip, this. The kids actually practice numeracy skills at well above level four as with unerring accuracy they work out exactly what combination of fridge magnets, invisible ink pens and blackjacks they can get for their pocket money.
2.30pm: Final headcount and back on the bus. Find myself sitting next to Luke, and get him chatting about the flat he's just exchanged contracts on.
"And do you share it with anyone?" I am about to ask, when the coach screeches to a halt.
A cry: "Miss! Adam's been sick down the driver's neck!" Thursday July 23: Sports day looms, and this year I'm the organiser.
Get all the kids together in the hall to explain what is going to happen, and in particular the rules of one giant game which gets played at no other time of the year.
Talk going well - kids excited but enraptured, Executive Briefcase smiling supportively - and have just paused for dramatic effect when with exquisite timing the loudest fart ever emitted rumbles round the hall. Riot ensues as kids find the culprit.
Don't think I'll ever achieve gravitas.