However, when you don't know what you're looking for then how do you search for it or know when you see it?
This is legitimate, especially for vague questions and ones that use terms likely to match an impossible number of topics. Search isn't going to be intelligent enough to answer complex contextual queries for a while yet.
One of the most asked questions is: "how do I merge 2 sketches"
Yep, I've seen that one a lot. This question shows a fundamental lack of understanding on the topic of programming. Like, you can mix one sketch that is blue, one that is yellow, and get one that is green. There's just no telling if they're compatible in a copy/paste kind of way, so you can't ever build a procedural approach to this problem. It requires creativity and understanding of the code -- and based on the question itself, you can bet that level of understanding is absent. What can you do? Learning curves are a .... pain.