It's easy to lose count of "final" deadlines that have been missed in the last five months of negotiations between Greece and its creditors. The latest is Sunday, when, according to European Council President Donald Tusk, Greece will face "really and truly the final wake-up call." It's possible the Greeks don't believe it is quite that final.

Some of what has gone wrong with the tedious bailout talks can probably be attributed to cultural differences, rather than ideological, technical or even substantive problems. Even though both Greece's former Finance Minister Yanis Varoufakis and his successor, Euclid Tsakalotos, are British-trained, the Greeks have been conducting the negotiations, well, as Greeks — and that may have amplified their northern European colleagues' exasperation and led to the current impasse.

European Commission President Jean-Claude Juncker first appeared nonplussed and then visibly angry when Greek Prime Minister Alexis Tsipras seemed to agree to certain terms behind closed doors, then turned around and declared the conditions "absurd" to the Greek Parliament. "I don't have a personal problem with Alexis Tsipras, quite the contrary," Juncker said. "He was my friend, he is my friend. But friendship, in order to maintain it, has to have some minimum rules."