A few years ago, airports across Europe started introducing a new security system (for example, here’s a news story about Dublin in 2016) with two improvements over the old system:
No taking out of laptops &c. Just put everything in a single large tray.
Parallel loading: instead of a single queue, multiple people are able to put their bags on trays in parallel loading stations.
Together, they make the process much faster.
I remember when Frankfurt Airport first introduced this. Despite the theory, it didn’t really work. People were taking out their laptops anyway (as they had been trained to do before this technology became available) and they were often refusing to parallel load because it seems impolite. The staff kept telling people to move forward to the available loading zone, but people were effectively refusing to do so.
People thought they were being polite, but the results was that the queues were taking significantly longer than they should. Normally politeness is pro-social,1 but in this case, it leads to anti-social results.2

Technology requires changes to cultural practices and what may seem pro-social (strict queuing) becomes anti-social when you need to move forward and take advantage of an open slot so that the line as a whole moves faster.
Often, when I want to tell a story from something that happened but not single out the individuals involved, I will make it vague and schedule to the future. If you ever read a tweet of mine about some peer review experience, that probably refers to something that happened 6-18 months prior. This time, however, I plan to write about such a common occurrence that it would not help to schedule it for the future.
I regularly travel somewhere and meet someone who will say something like I have been using SemiBin and I have a question for you and proceed to ask a question). I realize that often the person is just making conversation, but sometimes people do seem to have had that question for a while and even been stuck in their work.
An even weirder version of this phenomenon that I think every other “traveling salesman of second-hand ideas” (as Hayek called academics) has encountered is to travel to some institute to discuss your work and then meet with folks over Zoom. This is normally a small minority of people, but it does beg the question3: why did I have to travel to meet with these people on Zoom? Couldn’t I have met with them on Zoom from Brisbane?
Here’s the thing: you don’t need to wait to meet me in person to ask your questions! Consider this post your permission slip to email me (us, if it refers to my research group). We prefer if you use the corresponding mailing-list (or, if relevant, open a Github issue) as the pro-social thing to do (because it enables us to answer multiple people at the same time and creates a public record as there are probably others with similar questions).
Maybe it feels like skipping the queue to just ask a question if we have never met. Maybe spending a few hours on a flight going to a conference is an expensive and time-consuming ritual by which we allow each other permission to ask a question. It’s not the pro-social optimum.
Seemingly-incongruent addendum: I’m off to Melbourne tomorrow and giving a talk at Monash on Monday. Let me know if you want to get a coffee and talk science. But, feel free to get in touch even if you’re not in Melbourne!
A rationalist wanting to construct politeness from first principles may even write that “politeness is a set of pro-social heuristics.”
I imagine that Frankfurt Airport eventually educated its customers and people now do it well. I was already familiar with the process because Lisbon Airport had had it for years by the time it was introduced in Frankfurt and I traveled to Lisbon quite frequently.
This is the meaning of the phrase that makes sense.