Candy. In huuuuge quantities (at least for a 3 year old) generously distributed by advertising cars with big, powerful soundboxes.
Big, rotating whatsamacallit polyester ufo beasts spinning round and round forever being pulled by an aging tractor covered up in painted plywood and polyester while children go aaaah and ooooh.
Children dressed up as tigers, elephants, crocodiles, rabbits, clowns, vampires. Whole teenager school classes participating in the stately ‘stoet’ going down the street, dressed up as tables, violins, cave people. Old people dressed up as young people, young people as old.
Brass bands (with majorettes), sometimes from the next city, some from as far Hamburg or Rotterdam.
And a bit later and a bit further down in the city, the consuming of large quantities of alcohol and greasy food.