Cook the macaroni according to package instructions.
Add a little salt to the boiling water for flavor.
Drain and rinse with cold water, then set it aside.
In a large bowl, mix the mayonnaise, sugar, pickle juice, milk, and mustard.
Whisk them together until you have a smooth dressing.
Add the cooked macaroni to the bowl and mix it with the dressing until fully coated.
Stir in the chopped celery, shredded carrot, and finely chopped onion.
Mix thoroughly to combine all the flavors.
Season with salt and pepper to your liking.
Taste and adjust seasoning if needed.