How I discovered I was a developer:

The company had hired a pair of computer science graduates and we had been commissioned to build a magento store. Weeks went buy with limited progress, and missing functionality was met with protestations from the devs about unreasonable demands.

At this time I had been taken on as a designer / casual front end developer (though the focus was on design). I knew HTML, CSS and some very limited php and js.

We were severely over deadline, and seeing the desperation on people's faces I suggested looking into it.

I read the magento docs, got an install up an running, configured an installed plugins, integrated the theme using the complex multilevelled XML/phtml architecture magento uses and even got some of the more complex js functionality working using JavaScript.

In two weeks.

I'm now the lead developer