The first time Dave McGillivray remembers running — that is, running for a purpose, running with the intent of outpacing the competition, running with a finish line somewhere off in the distance — was when he was 5 years old.

“It was a 50-yard dash at Nutting Lake in Billerica on the Fourth of July,” McGillivray was saying the other day. “I was in street clothes. It was the first time I ever experienced the feeling of racing, and participating in an event.”

He won easily that day. But 50 yards didn’t quite cut it for McGillivray, who instead decided to just keep on running . . . forever. In 1978, he extended those 50 yards to the entire width of the country, running across the United States to raise money for the Jimmy Fund. He did it again in 2004, this time joined by a collection of veteran runners as they raised money for a host of children’s charities.

Each year, on his birthday, he runs his age. It started when he was 12. He is now 56. Ouch.

Oh, and he has run 125 marathons, including the last 38 editions of the Boston Marathon, which is an especially mean feat when one takes into account the Medford native happens to be the director of our esteemed 26.2-mile trek from Hopkinton to Copley Square.

“I had to decide whether to run the Boston Marathon or run in the Boston Marathon,” said McGillivray, who then hit upon the idea that, hey, if he planned it right he could do both.

It all started in 1988, when, after the world-class racers had crossed the finish line, McGillivray asked a state trooper if he wouldn’t mind driving him back out to Hopkinton.

“What, did you forget something?” asked the statie.

“Yes,” said McGillivray. “I forgot to run.”

OK, so that’s not exactly what McGillivray told the man in blue that day. But you get the idea: McGillivraywas put on earth to run, even if, these days, when it comes to the Boston Marathon, he is also running things. And what’s especially cool about this story is that it shows, even in this age of corporate sponsors and cash prizes, the Boston Marathon is, and always will be, a uniquely personal, uniquely local event whose participants, whether they’re from Kenya or Cambridge, Ethiopia or Everett, Ukraine or Uxbridge, instantly become woven into the fabric of our sports history.

Perhaps because he grew up a fan of the Red Sox, which has had a long association with the Jimmy Fund, McGillivray understands the connection with sports and philanthropy. Thirty years ago, when he started Dave McGillivray Sports Enterprises Inc., it just made sense to tie in with a host of local charities, because, as he proudly states, “Giving back is the essence of who we are.”

That’s why “DSME: Thirty Years Running Gala,” tonight (6:30) at the Quincy Marriott, deserves our support. Organizers are expecting upward of 450 people to attend the event, which, in addition to celebrating the 30th anniversary of DSME, will also be raising money for the its Children’s Foundation.

One program in particular is breathtaking in its cleverness. It’s called “Running in Places,” and it works this way: Participants from the Boston school system are taken to interesting locations around the city for the obvious purpose of running, but with the added bonus that they get to visit the places where the runs take place. A run along the Charles River, for instance, was the set-up to a visit to the Museum of Science. The idea is to teach kids about running and, hence, physical fitness, but also to introduce them to the city’s many cultural, historic and educational offerings. How awesome is that?

Tickets for tonight’s event, which includes dinner, are $75 and available at the door. Silent auction items include lunch with Sen. Scott Brown, a boxed DVD of “Saving Private Ryan” autographed by Cambridge’s Matt Damon, a jersey autographed by Lance Armstrong and a tour of the Kennedy Space Center.

For those who can’t make it tonight, take a moment and visit dmsefoundation.org and check out what McGillivray and his crew are up to.

This is great, great stuff. And to think it all started more than a half century ago with a 50-yard dash at Nutting Lake. Thank God little 5-year-old Dave McGillivray decided not to sit that one out.