By contrast, even though it is the same subject matter, chemical engineering is (correctly) perceived as being vastly more difficult than chemistry because it requires reasoning about complex system-level behaviors that has no analogue in chemistry. This creates the oft-observed effect that being skilled at chemistry has surprisingly low correlation with being effective at chemical engineering despite being the same domain.

But, unlike CS, there isn't this assumption that you've played around with organic chemistry and/or chemical engineering in your spare time if you want to major in it in college.