It's not nice to ask The Question

I recently heard someone ask a graduate student that they did not know, "So when are you going to graduate?" The asker was not being purposely unkind, but I felt that it was sort of a rude question. (Ultimately, it belied their lack of experience in academia.) When I was in graduate school, the only person who I did not mind The Question coming from was my very elderly grandparent, who had a much shorter time horizon than all the rest of my interrogators.

I bring this up in the context of my soon-to-be-retired father, who recently relayed to me how much he hates being asked "So when are you going to retire?" from his younger coworkers. I don't doubt that, just like the first case, it's an innocent question; however, I wonder if the asker realizes all the different questions that one is asking:

• When might you leave this job? 
• Do you have enough money? (By the time you're 3-5 years to retirement, the lifestyle at which you will be living is pretty much pre-determined, whether you're going to be in your vineyard in Tuscany or your trailer in Flagstaff... or your kids' basement.) 
• Did you know that you're much older than me?
• When might you leave this job? 

I confess that I have been guilty of speculating about my older coworkers' retirement schedules sotto voce, but I have not asked. Now, I don't think I will, either.