PARIS — You could say theirs is the Generation of Three E’s.

There is Erasmus, the European Union program that organizes and subsidizes student exchanges among universities across its 28 countries and elsewhere. There is easyJet, the budget airline that lets them hop between European cities as simply and cheaply as it can be to trek across town. And there is the euro, the currency used in most of the member countries.

Young adults are now grappling with what Britain’s vote to exit the European Union means for their profoundly European way of life. For them, it is perfectly normal to grow up in one country, study in another, work in a third, share a flat with people who have different passports and partner up without regard to nationality.

“It means that we are not going to be sisters and brothers of a big project,” said Antoine Guéry, 24, a Frenchman whose résumé and network of friends provide a crash course in European geography.