"Baseball stadiums hold some kind of magic for Erich," said Holly, now a project manager at the Rehabilitation Institute of Chicago. "He has a bizarrely accurate memory for when stadiums were built. That's how the trip started — we'd be watching baseball, and he'd start talking about the stadiums, and he'd ask if I'd been to each one. The answer was almost always no.
"So he started using his two superpowers — mapmaking and baseball knowledge — to put together a trip that would capture as many stadiums as possible."
The experiment was a success. "It was an amazing trip," Holly said.
The cross-border couple grew so close, in fact, that surprises became impossible. Therefore, there was no drama about if or when Erich would pop the question.
"We went to Montreal for Christmas in 2008," Holly said. "We found a jeweler and picked out the ring together a few days before the holiday. It would be ready on Christmas Eve, so we came back to the city that day.
"We went to the most beautiful place we could think of — the Oratoire Saint-Joseph, on Mount Royal. It's a gorgeous basilica and a historical site in the city. We went to a balcony near the top, with a great view of Montreal. It was snowing and freezing, so we were alone.
"Erich asked nervously if he should get down on one knee, and I said yes, despite the snow. So he asked me to marry, and I said yes. It was a lovely moment, but really it was the perfect culmination of our planning together, which is a good representation of us as a couple."
They were married July 17, 2010, the five-year anniversary of that first date at Wrigley Field. Last spring they had a baby boy they named Henri.
"I look forward every night to coming home and being able to spend time with Holly and Henri," Erich says.
Not to mention, they live close enough to Wrigley Field that they can catch a Cubs game whenever they want.
Love lesson: "I do recommend getting married as long as you have found the right person," Erich Neumann says. "I would not be enjoying my life as much as I do now if I were not married to Holly. The sense of security and having someone there for you is gratifying."