There is something strange about golf and how people score it. I find it interesting how many people say what their handicap is and it becomes apparent that they don't actually have a handicap. I find it also interesting that so many people brag about "I take every penalty stroke, even when..." and such. And I'm glad they do, at least they are doing that correctly. But I'd find it strange to hear someone say, "I beat my buddy at tennis yesterday, and hit all my winning shots within the lines." Why do we feel the need to say we played by the rules - it should be a given right?
I think it is a combination of the honor of keeping your own score - combined with how unbelievably hard it is to score "par". Maybe it is hard for people to admit just how poorly they scored compared to what is supposed to be done on a given hole. But it makes it hard for people to write down 8 on a par 4. Seems like it always ends up being a 6. Improved lies, mulligans, foot wedges, 4' gimmies, and of course forgotten strokes. And always the justification, "what the hell, I'm not a pro golfer or anything." But the same logic would not apply to the tennis court or basketball court. Can you imagine playing basketball and someone bounced one off the rim and then wants to count it? What the hell, I'm not a pro basketball player. If you aren't a pro golfer, it should be OK to shoot a 108. Instead, the logic becomes that since I'm not a pro my score should be magically lowered.
I play with someone different almost every weekend and I'd say I've only played with a handful that really kept a ball-down score. For some reason, golf is just different from other sports in this respect. I don't fault people too bad for it (unless they start getting loud about these great scores that they didn't actually hit), because it seems to be so prevalent that there must be something about human nature that causes it. Maybe Stanford should do a study.