First and foremost I was wrong thinking that I was smarter than others — that's not even how intelligence works.
Second I was wrong being so stubbornly pro-tabs / anti-spaces (for example). It doesn't make that much of a difference, so there's no point in being so passionate about it.
And third I was wasting everyone's time (and my persuasion powers) by not choosing my battles more wisely.
My suggestion would be nowadays: let's choose a popular style guide, set up a linter and be done with it.
This is probably the only useful takeaway, but can you explain why you were wrong?