My parents have been married for 40 years today. Wow. They made it through the 70s, 80s, 90s, and aughts (have we decided what we're calling that decade yet?).
My parents knew each other growing up, but not high-school-sweetheart-well, just as acquaintances. They went to high school together. Dad graduated two years before Mom. Mom sat next to one of Dad's sisters in choir. They never went out until they were in college, when Dad needed a date to a physics awards banquet (I come by my nerddom honestly, thank you). His sisters set him up with Mom. It's been a while since I've heard this story, so I'll have to ask them for the details again. Their first date was a science banquet, and I believe they went spelunking on their second date. Since they've been married, they've lived in Germany, Austin TX, England, and various small mining towns in Arizona and New Mexico. Side note - my sister had an obnoxious Texas accent when she first learned to talk, and an East Anglian accent by the time she was 4. Now she's a translator and interpreter in Japan, where native speakers routinely refuse to believe she's a foreigner when they speak to her on the phone.
I would give a woefully inaccurate summary of their life together, but I'm a little short on time for even an abridged version. Today I worked on "When I'm 64" in honor of my parents, because it celebrates the mundane little details of growing old together. Also, my dad turns 64 this year. So that's kinda cool.