How to Be Cool: Golf and Black Coffee

Many books and movies employ a kind of epithet for coolness. Just as Athena is "gray-eyed" in Homer's epics, various books and movies use a kind of short-hand to indicate that the character is, let's say, "the cat's meow."

1. Golf 

Numerous heroes, even Poirot and Columbo!, will suddenly hit a golf ball, a hole in one, to demonstrate that despite their finicky, absent-minded natures, they are just too amazing for words. 

A funny variation on this is that Murdoch cannot get good at golf and when he tries to help an Olympian golfer, he messes up the guy's game.  

But generally, yeah, being able to hit a golf ball is apparently really rad. 

Koichi trying to figure out his boyfriend's tastebuds.

2. Black coffee

This particular marker of awesomeness appears with Peter Wimsey. In addition, various aloof and cool heroes in manga dislike sweets. 

Regarding the later, in some cases, the heroes' love of sweets indicates honesty and self-knowledge, which becomes cool in its own right--

But still, a dislike of sugar remains a mark of grit and endurance--and therefore, coolness.