Cultural historian Christopher Cook says the fundamental change is that these celebrations used to be family affairs, private and inward-looking.

BBC: Why has everything become a costly milestone event?

Christopher Cook, a spokesman for the registry, declined to comment further.

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The achievements of trailblazers like Vasco da Gama, James Cook or Christopher Columbus can never be surpassed, so some might argue that real explorers are a thing of the past... adrenalin junkies with nothing left to search for?

CNN: Quest for exploration