For two hours I experiment with changing my position. I lie on my right side. I lie on my left side. I lie on my back. I try re-plumping my pillow and repositioning the duvet. As a last resort I heave several sighs that I hope won't wake my wife up.
"It's just nervous excitement," she mumbles. "Try to relax."
Eventually, I fall into a fitful sleep in which I wrestle with the fiendishly intractable problem of how to access and complete the new electronic lunch register. I switch the alarm off half an hour before it was due to wake me up and take a shower.
I never sleep properly the night before the first day back at school. After all these years, my stomach still churns in anticipation of a new class. As my bowl of cereal slowly congeals, I consider my options. What's the worst that would happen if I never went back? Then the prospect of watching daytime television for the rest of my life forces me to roll up my sleeves and steel myself for the year ahead.
My fears turn out to be unfounded. The first day back is characterised by good order. The children arrive neatly packaged in new uniforms, with scrubbed faces and tidy haircuts. Even Hayley, who normally looks like a Victorian street urchin 10 seconds after reaching the school gates, seems resistant to wear and tear. For the first time ever, she makes it to lunchtime with her plaits intact, her tie in place and no signs of marker pen on her clothes or skin.
And it's not just appearances that make the day go smoothly. This is a fresh start and everybody is out to impress. Rules are followed meticulously and instructions are carried out to the letter. In truth, it's all very unnerving. Even Jake - who comes with a history of anger management problems and a reputation for creating havoc second only to Genghis Khan's - smiles up at me like butter wouldn't melt in his mouth.
I smile back cautiously and double-sticker him for good behaviour. Perhaps it's the exhaustion kicking in but I have the curious notion that this is all a dream. It's like finding myself in a meadow, with a spring in my step, a song in my heart and a growing realisation that actually it's not a meadow after all - it's a minefield. And inside my head someone is screaming at me to wake up and smell the cordite.
By mid-afternoon the strain is beginning to show. A thrown pencil and a minor argument that ends in tears leave me feeling reassured that it won't be long before things are back to normal. I smile to think that in the not-too-distant future Jake will swear at me and storm out into the corridor. I sigh in the knowledge that within a week Hayley will lose her tie and go home looking like she's been dragged through a hedge backwards.
"So, how was your first day at school?" asks my wife, as we turn in for the night.
"Zzzzzzzzzzzzzzzzzz," I reply.
Steve Eddison teaches at Arbourthorne Community Primary School in Sheffield