When director Richard Linklater brought his Before Sunrise to the Berlinale in 1995, little did he know that he was kicking off what would become a veritable tradition. The film starred Ethan Hawke and Julie Delpy as two young students who meet on a Eurail train and enjoy a romantic walk-and-talk through the streets of Vienna before day breaks.

“We knew it was a risk making this film, but that’s why we did it on a low budget,” Linklater said at a festival press conference. “I don’t think they are going to lose money on this film.” That was something of an understatement. The $2.5 million Castle Rock production not only earned Linklater the fest’s Silver Bear for best director but, released by Columbia Pictures, went on to become an indie hit, grossing $22.5 million worldwide.

And so nearly a decade later, Linklater returned to the festival in 2004 with Before Sunset,...