There is one line of questioning that I think may represent a fundamental disconnect between how entrepreneurs and venture capitalists look at the world.

FORBES: Why Startup Timelines Requires Stamina

Above all though, perhaps David Cameron's calculation was that his defiant Downing Street news conference would make him look like a leader at a time when his own party has been questioning how long he should carry on in the job.

BBC: Press law - So why did he do it?