Yeah, the dairy thing is so hit or miss. For me, it was sugar in general, not just soda. I cut out obvious stuff like candy and pastries, but the sneaky one was flavored yogurt and sugary coffee creamer. My skin calmed down a lot after a couple weeks of checking labels for added sugars.
Wow, that's awesome about the cola! I read an article recently that said cutting out dairy milk can make a huge difference for some people. It talked about how the hormones in milk can actually trigger breakouts for a lot of adults. I tried switching to almond milk in my coffee for a few weeks and noticed my skin got less angry.
Actually gotta disagree on the dairy thing, @eric_hunt. My cousin cut it out totally and her skin got worse, so it's not a sure fix for everyone. Sometimes stress or just genetics are the bigger deal. Plus, a lot of those studies aren't super clear cut, and dairy has stuff like calcium that's good for you.