There’s a very specific moment in Vienna when you realize winter is finally over.

It’s not a date on the calendar. It’s not even the first day it technically becomes spring. It’s that first truly warm day when the sun feels different. When people linger a little longer in the parks. When suddenly the city feels like it’s exhaling.

We had one of those days this week.

It was warm enough to leave the house without a coat, warm enough to walk without any real destination,...