Twenty-six years before Fifty Shades of Grey, the late Chrissy Amphlett, frontwoman of Aussie rock band Divinyls, pointed out that in affairs of the heart (and other body parts) "it's a fine line between pleasure and pain".
Likewise sport. Martin Guptill played the innings of the Cricket World Cup and made many commentators' team of the tournament, but if the West Indies hadn't spilled a relatively straightforward catch he wouldn't have done either.
Likewise war. The Battle of Waterloo ended the first French Empire, consigned Napoleon to exile on a volcanic rock in the South Atlantic and ushered in 50 years of peace in Europe, but according to the victorious commander, the Duke of Wellington, it was "the nearest-run thing you ever saw in your life".
When it comes to things that could go either way, the just-announced embryonic deal over Iran's nuclear programme takes the cake.
Led by the Presidents of the US and Iran, some are hailing it as a historic breakthrough that defuses an explosive situation and has the potential to jolt the Middle East out of its death cycle of terror, civil strife and proxy war. Others, however, are denouncing it as a monumental folly likely to end in a mushroom cloud.
From Tel Aviv to Texas the Iran deal is being compared to the 1938 Munich Agreement. In this scenario, Iran is Nazi Germany, Barack Obama is Neville Chamberlain, the hapless dupe of a British Prime Minister who swallowed Hitler's lies hook, line and sinker, and Israeli leader Benjamin Netanyahu is Winston Churchill, the voice in the wilderness speaking the inconvenient truth that no one wants to hear.
Munich is synonymous with the policy of appeasement " making concessions to a tyrannical regime with imperial ambitions in the hope it will be placated and modify its behaviour accordingly.
Chamberlain conceded the German-speaking Sudetenland region of Czechoslovakia in return for Hitler's assurances that there'd be no more land grabs. He returned home to a hero's welcome, waving a piece of paper and proclaiming that he'd secured "peace in our time".
But Hitler was far from satisfied. A year later he seized two more Czech provinces before invading Poland, thereby triggering World War II.
With the benefit of hindsight, the whole appeasement narrative seems somewhat overblown. It suggests Chamberlain set such store by his piece of paper that he sat back twiddling his thumbs while Germany prepared for war. In fact, he stepped up rearmament, pressed France to do the same, doubled the size of the Territorial Army, created a Ministry of Supply to expedite provision of the armed forces and introduced conscription.
Eight months into the war Chamberlain gave way to Churchill, although he continued to play an important role in the War Cabinet. After his death in late 1940, his enemies had a field day, notably in the form of a pamphlet Guilty Men.
The demolition of Chamberlain's reputation was completed by Churchill in his six-volume The Second World War. As the man himself purportedly said, "history is written by the victors".
A footnote: an arguably more foolish and catastrophic example of appeasement occurred at the Yalta summit in 1945 when Churchill and US President Franklin Roosevelt swallowed Soviet leader Joseph Stalin's promises to allow free elections in Eastern Europe. Churchill is probably the most quotable and quoted statesman in history, but you don't come across this gem very often: "Poor Neville believed he could trust Hitler. He was wrong. But I don't think I'm wrong about Stalin."
Churchill's criticism of appeasement wasn't that it promised peace while delivering war but that war was inevitable so it was humiliating and counter-productive to cut worthless deals at the expense of third parties. "England has been offered a choice between war and shame," he said in the post-Munich Commons debate. "She has chosen shame and will get war."
The current situation echoes Munich in one respect. Critics of the deal argue the US shouldn't settle for anything less than a capitulation that would render the Iranian regime's position untenable. Given the regime will never agree to such a deal, the critics are following Hitler's example of pretending they want to give peace a chance while being hell-bent on war.