Manager: We (meaning you) need to do task A. How long will it take?
Me: Task A will take X days to do.
Manager: That seems awful long.
Me: How long do you think it should take?
Manager: It surely could not take any longer than Y days.
Me: Ok, it seems you have an answer to your question then.
Later:
Manager: It’s been Y days, why isn’t task A done yet?
I had this for about 6 years running, eventually we marked the bottom 90% of the heap “won’t do.”
This was in the early 90s, I kept track of the items on “sticky note” software on my Windows 3.1.1 desktop. At the top of the sticky note I placed a gothic font “The Creeping Feature Creature” label. Two or three times a week my boss would stop in on his jog (he lived a mile away) with a new idea, and we’d prioritize it into the stack - most new ideas went just below whatever I was still working on. Every few months we’d reshuffle the list. It was a workable arrangement because I was the only programmer and he was the company owner.
When we started working on bigger contracts for outside customers, he shut the hell up and let me get the contracted work done.