I would never name my kids Karen, Susan or Debbie. Not because there is something wrong with those names, but EVERY girl in my school seemed to have those names. So (a) they seem overdone and (b) I have traumatic encounters with girls who had each of those names.
I also swore I would never give my kid a middle name of Ann or Lynn because everyone seemed to have those names as middle names. But then I married into a family who had a tradition of giving all the girls middle names of Ann in honor of my MIL's mother. And the day I found out I was pregnant with Mini-Mac, my friend Lynn died. So I was torn. We actually contemplated naming her Lynn Ann - double whammy! But Mr. Mac didn't like that and had no trouble breaking the family tradition so she was saved from that fate.