Which is usually manifest in the ones who are so impervious to life’s lessons that they get a 2nd PhD. The principal life lesson from getting a PhD is that it was a waste of time. I have known engineers who stand on their MSs and try to hide the fact that they got a PhD so they don’t have to explain why they chose to waste another 3 years of their lives.
My mom didn’t turn in her thesis at the last minute because she realized getting her doctorate would put her out of a job.