I have no science A-levels, no science degree and, until 2011, no real interest in, or understanding of science.

I scraped 2 Cs in GCSE Double Science at school.

I am also a qualified chemistry teacher. Legally, in England, I can teach up to A-level science. And I don’t, because I really shouldn’t.

The fact that I managed to qualify as a teacher isn’t remarkable. The fact that I managed to qualify as a science teacher, get hired as one and be in demand as a supply teacher is testament to the abysmal state of the English education system.

It was a total accident.

I had graduated in the last recession and was fed up of working at McDonalds, still. So I applied for history PGCEs (the teaching qualification in England, Wales and NI). Unfortunately, there were thousands of applicants with real history degrees so my archaeology one wasn’t getting anywhere. Let’s be fair, if you have a history degree, your options are Sainsbury’s or teaching.

At the same time, my boyfriend was applying for Physics PGCEs. We were both unsuccessful for different reasons. But he got an email saying he’d had his £16 GTTR (UCAS/CAO for teachers) application fee refunded because he’d applied for a science subject.

I was on the bones of my arse eating once a day, so when my application moved into clearing, I applied for science to get my £16 back. I heard nothing about my refund so I decided to write the whole thing off as a bad job.

I got a phone call a week later offering me an interview for a science PGCE.

I had to take in some kind of visual model and explain how I’d use it for teaching.

I made H₂O out of plasticine. The night before the interview, I told my biochemistry MSc student friends about the interview.

They laughed and laughed. When they were done laughing, I proudly showed them my plasticine H₂O models. Then they laughed some more.

“Torie,” Gareth said, “You’ve got two oxygen and one hydrogen per molecule.” He looked at me like I should immediately realise my error.

I looked at the plasticine. “Is that wrong? It’s water. H₂O.”

He laughed again.

“It’s two hydrogen and one oxygen.”

“Ohhh. I thought it was H and two-O.”

“No. H-two and O.”

“Oh.” I laughed too, because honestly this whole thing was so preposterous. I thought I was the last person in the world who should be teaching science (tragically, I found out when working on supply that this wasn’t true).

I hastily reworked my models and took them in the next day. Talked the interviewers through how I’d teach with them and why. Then there was the one-to-one bit.

“You failed maths AS-level. You’d be a good candidate for the physics enhancement course which would enable you to teach up to A-level physics.”

“But… I failed it.”

“But you did the course.”

Sidenote, I didn’t just fail, I got 7 out of 300 on the exams.

Also, my boyfriend with a physics PhD was sitting at home twiddling his thumbs not able to get a PGCE for no apparent reason. And here, they were seriously considering giving me a physics PGCE.

I decided this had gone on long enough.

“Look, I really couldn’t take the physics one at all. It took me three goes to get GCSE maths. I’m sorry. Do you have biology? I’m better at that.”

“We don’t need anyone to take a biology conversion course. There are billions of biology graduates who go into teaching. But we’ve got a chemistry enhancement course. You could do that, I suppose.” The interviewer was visibly disappointed that I didn’t really think I’d be a great candidate to become a physics teacher. Me, with two A-levels (history and geography), a BTEC in media studies and a BA in archaeology. But I was stuck in a situation that was preposterous. And I was starting to talk myself into it. Maybe I could do this.

Partly, though, I didn’t want to say no because I was very aware that there were so few women in STEM and while I never, ever should have been one of them, I thought maybe I could inspire girls who had an aptitude for science to do STEM.

If I’d been a bit better at history I might have reflected that nearly every monumental cock-up in the whole of human existence has been borne of someone with good intentions going about something the wrong way or trying to do something they really shouldn’t.

“Okay.” I was worse at chemistry than physics. But at least I wasn’t betraying my boyfriend (ladies, this 100% is not how to make career choices). Two years later, I completed my chemistry PGCE (the hardest thing I’ve ever done) and started my first teaching job.

I got sacked three days before Christmas.

But that had nothing to do with my subject knowledge and everything to do with politics. I’m worse at workplace politics than I am at maths.

I never did get my £16 application fee back though.