This comes up in lots of different contexts
but it boils down to “I know you’re busy, but here’s a simple and obvious (according to my cocktail party understanding) solution to the problem I’m having. I need it working tomorrow.”
After all, how hard can it be to write a script to automate it? You already know how to do it. Response times for your web query are slow. Just add a cache. It’s simple.
It’s simple on the surface, but when you dig into it there are a lot of details. Lots of fiddly bits that need to be just right, or you end up in worse shape than you were before. The first implementation of the script hides error messages, or worse, ignores errors and continues on, doing the wrong thing. The cache you just turned on gives inconsistent results depending on when you ask and where you ask from. All of these things are correctable, and when you get it working you are in better shape, but it’s not as simple as “Just cache it”.
I can be guilty of this myself. I used to say to people, "While you’re in there, can you make this other change?" While it might be the right time, it’s never as simple as that. Neither I, nor anyone else should expect it to be, yet we keep doing it.
So Just Remember, when you hear someone say “Just ….”, it’s never as easy as it sounds.