So painfully true. This is one of the very first things I try to determine when I'm interviewing someone: do they have the capacity to actually figure out how things work, or are they doing something rote that they picked up along the way and will just blindly change code until "it works" when they hit a serious obstacle?

And I've also worked with plenty of very senior engineers who will blow smoke up your ass when you're really down in the weeds and you want to do "root cause" analysis.