The day starts with a high, as I race to the door, hopeful that an abundance of pink envelopes has jammed the letter box. Followed by the inevitable low as I discover that the post consists only of bank statements and a flyer for a local oven-cleaning service.
Another high on getting to school and watching the deputy head's face go scarlet as he tries to hide the novelty Valentine thong which has been put in his pigeon-hole.
This is followed by a lovely, protracted, all-day high, while I dreamily wait for the school office to phone and let me know Interflora has stopped by.
This ends with a resounding low when it dawns on me that the only thoughtful gesture of the day is a home-made card from a six-year-old which says: "To Miss Lemon. I love yoo sow mutch. X". Thoughtful, but utterly depressing.
Yet another low when I get home to find my boyfriend (also a teacher) proudly brandishing a pile of tacky cards - one of which, he claims, is not from the usual group of giggling Year 9 girls but is, in fact, from a bona fide, mystery member of staff.
"Lucky you," I sneer; then cheer up as he pulls out a bottle of my favourite pink champagne. Having drunk it all, I then hit my final low, when I remember that it's a school night.
Now here is the good news. This year, February 14 is in half-term, which makes it much easier for me to hide beneath my warm duvet and dedicate the entire day to the one love that never, ever lets me down - chocolate Louisa Leaman is a London teacher