As systems engineers, a fair amount of our job is making the vague specific.
The customer wants something. OK. Customers want things. They want you to make it a little like this [holds hands apart], maybe with a little... I don't know... [fills cheeks with air like a balloon]... yes, and not too expensive. Of course this exaggerated, but not by as much as we wish it was exaggerated.
It's not a problem, though. It's a game. How do you figure out—elicit is the fancy term of choice—exactly what the hell the customer wants? Underlying the game is a deeper question: How do you help the customer figure out what the customer wants? Suffice it to say that there are a lot of questions, and a lot of assumptions fished from the depths and put on display because, honestly, no one really understands how many ideas they've assumed into a design until someone shows them. And then there are the things that affect other things (and vice versa). And the technology that may or may not be ready on time. And on and on.
Suffice it to say that there a a lot of questions to piece together what a customer is thinking.
This gets me into trouble at home. My wife has an idea of something for the yard—maybe just a design element like a trellis, or something general like how the yard should be shaped. I know that this is going to fall into my job jar. (I'm not the best at landscape construction, merely the best one within a ten-foot radius.) I know how to figure out how much wood to buy, how many blocks and rocks, how to get the materials to the backyard, how to prepare the construction, how to cut things, etc. To do that I need to figure out where the design element should go, what it should be made out of, how big, what color, etc. I know roughly what to ask to turn the dream idea into something real.
"Roughly" is probably the key word there. At work, whaddyawant questions are an all-the-time occurrence. That's how things get done. We expect to give and receive those questions all the time. At home those questions go over... poorly. Sometimes the ideas aren't supposed to be specific. Sometimes they're ideas that will go somewhere and will eventually turn into something real—those will need specification. Sometimes ideas are just seed ideas and need to be planted out loud, then eventually they'll grow into an idea that will be ready to harvest—let those early ideas be as they are. Some ideas are just idle thoughts. Idle thoughts are just that. Not every idea needs to be specific—enjoy the casual thoughts that help the day go by, then let them go.