Eighteen — the age of majority

In most countries of the world, 18 is the official age of majority: the right to vote, make contracts, marry without parental consent. This number has become a universal symbol of the transition to independent life.

In Jewish numerology (gematria), 18 = 'Chai' (חי), meaning 'life'. The tradition of giving monetary gifts in multiples of 18 has existed for thousands of years. This is one of the most important numbers in Jewish tradition.

On June 18, 1815, the Battle of Waterloo took place — Napoleon Bonaparte's final defeat. This battle permanently changed the map of Europe and ended the era of the Napoleonic Wars.