Recently, I watched a video featuring a guy narrating the One Piece characters that are in Jump! Ultimate Superstars for Nintendo DS. I don't think this guy was particularly familiar with One Piece, because he mispronounced Luffy's name (luff-ee instead of loo-fee). I'm not holding this against him, as it's an easy mistake to make and, in fact, one I myself made when I first got into One Piece. Which led me to thinking:
How many people here on this very forum made that identical mistake (calling Luffy "Luff-ee") and how/when did you learn what the name was intended to sound like?
As I said, I made it myself at first. It was an early issue of US Shonen Jump (I forget the exact one) that corrected me. It specifically pointed out the proper intended pronunciation of Luffy's name.