I've had this prompt also. The way I interpreted was that it's asking if you encountered something totally unexpected which taught you something important.
Here was my example: I worked in a Urology office as a receptionist. About 80% of our patients were men above the age of 50, most coming in for some sort of sexual dysfunction. My coworker was a 21 year old female and I was a 22 year old male. I was shocked at the number of patients that absolutely refused to talk to her. About 15-20 times a day, she would pick up the phone and the person would immediately say "Can I speak to a male please?".
I really had not expected this. But it taught me a lot about patient-provider communication and the importance of making sure that patients are comfortable in communicating important aspects of their health.
