They met through a mutual love of music, through a series of music festivals.
"You have a degree in math? I have a degree in math!"
"You play theremin? I have a theremin!"
"You're an actuary? I wanted to be an actuary when I was in 5th grade!"
"You're part of a 'Buffy the Vampire Slayer' fan group? That's my favorite TV show of all time!"

The similarities went on and on: An older sibling they each found out about as adults. A history of high school theater. A love of the mid-century modern aesthetic, of sci fi / fantasy, and of way too much garlic.

But then they realized the more important things: How much fun they have together. How they are both optimistic and positive about life in general. How well they work out disagreements and solve problems. How they work as partners. How affectionate they are to each other.

It took a long time for them to find each other. Then it took a long time before they realized what they had found. Then it took a long time to make their long-distance relationship work. It will be a long time, still, until they can actually live in the same state. But there is no doubt in either of their minds that their journey has, and will continue to be, totally worth it.