In the example quoted below, I used surprised with intended meaning "jolted from naïveté", but wasn't satisfied with it. Also, I wanted to avoid implying that discovering the mentioned fact made me omniscient, jaded or both. The fact wasn't just something I didn't know, it was something I didn't know because I hadn't bothered finding out about it.
Here is the instance where I used surprised. It was on another SE site, so rather informal:
I was actually surprised to find there is a whole field devoted to researching and mitigating jury biases, though their research could arguably be easily used to exploit jury biases.
(I study psychology, so not knowing this was kind of ignorant.)