"How old are you, Miss?" Lewis asks, no doubt wondering whether I'm older than his grandmother. "Never ask a woman her age, Lewis," I reply. Lewis looks cowed, I feel guilty, because I don't want to dent his curiosity. "Very old, Lewis" I joke and he smiles again.
"Actually, I'm an NQT," I try to say casually to those in the staffroom asking about my experience. They look at me with amazement and a touch of distaste. They try to put a "good for you" look on their faces but I can see them struggling to disguise that they actually think I'm mad.
I recognise the sentiment in my own response to friends who have had late babies - the unimaginable horror of having to go through all that again.
I'm 47, but I still feel 25, so I just can't see what the matter is. Surely I'm just like the other NQTs? But then they speak to me as if I am their mother and I realise I'm not. I confide in my own mother, who unhelpfully says: "Don't worry, you'll soon be coming up for retirement, dear." I look in the mirror and think that perhaps this late change of career direction is a bit eccentric.
While my young and beautiful PGCE colleagues were, one by one, picked for NQT posts by good looking heads, I'm still left, like a spinster, on the supply shelf.
To be honest, my interviews have been a catalogue of disasters. I have so much experience that the headteacher ends up looking bored and I've blown it. "I used to be a director, I used to train senior managers in creativity, you know," I gibber. "Both my own children are dyslexic and I've been totally involved as a volunteer with their primary schooling," I add.
There's a glazed look. Just stick to your teaching practice, just talk about your teaching practice. I mutter my new mantra on the way to the next interview. I rapidly start thinking this won't show them the real me and start talking about my teaching abroad and ... oh no, I've blown it yet again.
But even if it takes a thousand interviews, I'm determined to do this. I'm just waiting to meet the headteacher who will sweep me off my feet.
Mandy Reddin is a supply teacher in West Sussex.