Yesterday, I had a meeting in a public building. As I approached the elevator down a long hall, I saw what appeared to be a woman and her mother standing, staring forlornly at the elevator. They just stood there, looking unhappy. The button wasn't lit, so I knew they hadn't pushed it. I walked up, pushed the button, the door opened, and they jumped in right on my heels.
I couldn't tell you if either of them had a PhD. But, yes, some people really ARE that "challenged," especially when in an unfamiliar environment.