I was shocked to discover that "How To Win Friends and Influence People" by Dale Carnegie was heavily rewritten by his wife after his death. I had two copies of the book, and sure enough, one was the old version and the other the new. The new one did not withstand scrutiny.
Hacker News' founder Paul Graham also recommends that you read the original version[1]. I'm curious to see examples of what was changed in the revision. I read it myself a long time ago, but I don't know which one it was and wondering if I missed out on the better version.
1. Letters That Produced Miraculous Results - cut because correspondence norms had massively changed between 1936 and 1981
2. Seven Rules for Making Your Home Life Happier - cut because its 1930s-era perspectives on marriage and domestic life didn't age that well
Personally, I think some of the edits in the remaining sections are more controversial than the removal of those two sections. I think the revision lost quite a bit of Dale's charm and just felt a bit less idiosyncratic in a bad way.
