Where were you when the Berlin Wall came down? Apologies to anyone under the age of 25 or so, but it was an unforgettable moment, reinforced by the images of Berliners vigorously demolishing the barrier that symbolised the cold war.

So when will the current crisis have its 'where were you' moment? Perhaps our news channels are so fragmented that such episodes will never occur again. Alternatively, it's already happened but we're still waiting for hindsight - and the archive libraries - to remind us how to remember.

When my glass is half full, I reckon that the only such moments in recent months occured on November 4 last year and January 20.  

When things aren't so bright I figure that it just hasn't happened yet. Will Downing Street Twitter the nationalisation of RBS? Let's hope not.