In my opinion, the PhD changes the personality over time. Not everybodys', but it certainly has an impact. If you are a cheerful, friendly, open person now, expect to be an entirely different person once you get out of this. What I currently don't know is if the damage is only temporarily or not. If I look at older academics around me I expect the worst, to be honest.
Not trying to find excuses, though. Before I started the Ph.D, perhaps I wouldn't have considered the OPs' question as silly, but now I do. So, I have changed, not the question.