As a new owner, I tried very hard to research my Harley purchase, ask questions at the dealerships where I shopped and the one dealer where I did eventually purchase my bike, talk to friends, etc.
Despite all of this, I am still learning, and some of the things I am learning conflict with what I was told (and what I was sold) when I did pull the trigger back in spring of this year.
Example - I put a PCV and headers on my bike when I bought it based on advice from the dealer about keeping the motor cool, and now an indie is telling me to take them off and replace with headers that have an O2 fitting and TTS. My complaint to him was that my mileage seems to suck (28 mpg or so on my '12 Ultra Limited) and he tells me that this will fix that issue.
Man oh man. I guess the learning never stops. Or the cash outlays.
That's the style!