Under optimal conditions, running the Boston Marathon is a long slog, eased in no small part by the cheering throngs. If it it’s true that the crowds from Hopkinton to Boston are unmatched by any other major race, the traditional outpouring of thousands of spectators took their support to a whole other level on Monday. Like a lot of runners, I can say -- with little doubt -- that there’s no way I would have made it to the finish line without your high fives, your ice cubes, your backyard hoses, your screaming for me and other complete strangers as if we were your children, even when we were limping.