I’m old enough to remember when Germany was divided.

I visited West Germany in 1984. And although I didn’t pass through Checkpoint Charlie—as many American tourists did—it still looms in my imagination as one of the most poignant symbols of Communism’s failed dreams.

Today marks the 20th anniversary of the day the wall came tumbling down. In history’s hindsight, it’s hard to grasp that some 10,000 people tried to escape East Berlin, and that an estimated 200 died in the attempt.

It’s also hard to imagine that Germany’s two-term chancellor, Angela Merkel, was among the first East Germans to walk into the West.

“I dreamt of the Beatles and of the outside world with all of its possibilities,” Merkel said in a recent interview.

I’d bet she never dreamed she’d be chancellor of a unified Germany.

Today is truly worthy of a global celebration. In Germany, everything has changed in 20 years.