I'm glad it worked out. I'm going to give you some advice that was probably the best thing I ever learned for my career: your job is to figure out how to communicate effectively with people, no matter how stupid they are, and no matter what is in your or their job description.
I absolutely understand the frustration. I was almost always the smartest person in the room, and I have very little tolerance for stupidity. And when it is someone who is supposed to know more than me and is getting paid more than me, well, that's the cherry on the sundae.
But here's the thing: when you're smart, sometimes you see things that other people don't. To you, it seems obvious -- because you're smart! But other people may need you to put the dots very close together to get there. I would get frustrated all the time, because I'd say something that seemed very obvious, and someone wouldn't follow, and I'd think they were being intentionally oblivious, when the reality was that I had leaped ahead in the conversation, and they were completely lost. So if you want to get the job done effectively, you need to figure out how to change your own message to say it in a way that your audience understands. The best thing that ever happened to me was when my mentor took me aside and told me my impatience was making the guy I worked for feel stupid. Now, I knew the guy I worked for was in fact brilliant -- so if I was making him feel stupid, I was the problem.
The other thing to keep in mind is that no matter how smart you are, you do not have perfect perspective. Jobs need all sorts of people with all sorts of skills, and we only see one part of what other people do and have no real insight into why they were hired or how they do their job overall. And people themselves are driven by different things and communicate in different ways. For ex., my own DD is pretty damn smart, but if you tell her things orally, most of the time they don't stick. Turns out her intelligence is like 95th-99th percentile, but her audio processing abilities are more like 8th percentile -- so for her, it really does go "in one ear and out the other," because it just doesn't stick. Other people may be dealing with reading comprehension issues, or maybe they're so overworked they don't have time to really dive in and understand things and just want a bullet point summary.
If you can stop seeing it as "smart vs. stupid" and start thinking of it as a personal challenge to figure out how to communicate effectively with all the different types of people around you, that will serve you very well long-term. Because in the end, all the company cares about is getting the job done. You can be the smartest engineer the company has ever seen, but if you can't convey your ideas clearly to everyone else who needs to work together to make things go, all those brains don't help the company one bit. OTOH, if you can be the guy who can explain the business people's concern to the engineers, and the engineers' problems to the business people, then boy will you be popular. Just ask my DH -- he took his PhD in E.E. and made a career out of translating between those two groups (not to mention the customer).