Monday.

I was trying to explain to a non-Bostonian yesterday what Patriots’ Day is and what it feels like to a native.  Although I have lived outside of Massachusetts for nine years, I often forget that the third Monday in April is just the third Monday in April to the rest of the country (except, apparently, Maine, which also celebrates it.) So, while everyone is undoubtedly shocked and saddened by the events in my beloved Back Bay yesterday, I think the more nuanced sadness of it happening on this day in particular might not be immediately understood. Loss of life and injury is horrific. I know this. The shock of a really loud noise when you’re not expecting it is traumatic. But what has gotten inside me is not the details of a national tragedy.  It’s the sadness for my people, celebrating something that is only ours.

Patriots’ Day commemorates the battles of Lexington and Concord, which were the first battles of the Revolutionary War. This is a part of American history that Bostonians take pride in. It’s the history that is  woven into the fabric of the city. It’s where it began. It’s the stories, repeated in every grade school classroom, enhanced by field trips to the battle sites, ground into the red brick of the cobbled sidewalks winding along the Freedom Trail. Paul Revere’s house, the Old North Church, Bunker Hill. Sure, Bostonians love the Red Sox and our accent and even our reputation as “Massholes,” but this is Boston. Our place on the timeline of the American story.

And then there’s the part about springtime. Tree-lined Newbury Street, boasting tiny yellow-green buds, swan boats returning to the Public Garden, and the finish line being painted on Boylston Street. It’s also the beginning of April Vacation for school kids. A week that families often take off together, taking day trips in and around the city, gearing up for summer. It’s a hopeful, celebratory time that belongs to Bostonians alone. It’s inherently our day in our city and even though there are throngs of visitors and hundreds of thousands of people who celebrate it as Marathon Monday along with us, we are the gracious hosts.

Let’s try this: Imagine you’re throwing your annual garden party on the prettiest day of the year. You’re wearing your sweetest spring frock (or dandiest seersucker suit) and you’ve baked cookies. Lots of delicious cookies and you’ve concocted a sweet and tangy limeade. You wake up early that morning and your house smells like a mix of lemon Pledge and blooming stargazer lilies as you lay out the guest towels on the bathroom counter. It’s sunny and warm. You’re smiling — not at anything in particular, but just because. Your friends and family start arriving and they bear gifts and food and they’re already laughing. You join them. It’s sweet and fun and you can  see the tangible fog of winter lifting away from the city skyline. You’re embracing people and drinking wine and the clinking of forks against delicate little plates is at once replaced by an explosion. Sirens and smoke and screaming and blood. And fear.

That’s what it is. I wasn’t there on Monday. I don’t live there anymore. I was neither at the marathon nor in the city that I call home. But I am a Bostonian and I felt that bomb in the middle of a garden party from 300 miles away. That is what it’s like to have been a Bostonian on April 15, 2013. Best as I can tell it.