Learned about Utility-First CSS
While working at SocietyOne, I was introduced to the concept of Utility-First CSS as the previous developer, Simon Vrachliotis had built the website in Tachyons.

At first, the concept of all those utility classes mucking up my HTML made my eye twitch. It was gross. It was heavy. The classes were so difficult to understand! I hated working with it every day!

But then as I got used to it, I started thinking about it. If I'm building everything in a component in my templates, what does it matter if it's ugly? I just need to read the component that I'm working on, right? And if I'm defining my values ahead of time, I have all the tokens and values at my fingertips and I don't have to go back and write the same values over and over.

But the biggest thing? The truly greatest thing that I learned from this experience? It was the fact that I didn't have to worry about what to name something in my CSS to be able to reuse it. There is a certain freedom I feel when I no longer have to figure out how to de-specify a class so that it makes sense to work in other UI patterns across my site or app.

Thus, my love of Utility-First CSS was born. It later blossomed into an appreciation and reliance on TailwindCSS, but that wouldn't be for another year or so.