Milk is first because you can pour any amount of milk you want, then when pouring the cereal, it becomes a test of self control to yourself. You have to control yourself on putting the perfect amount of cereal you consider that wouldn't overflow the bowl

But why go through that? Because you should always pursue ways on how to improve on yourself in your daily basis one way or another. Another great reason to pour the cereal last, is so you can get the greatness of both worlds, soggy cereal and crunchy cereal, it's a special mix that you feel in your mouth that is almost impossible to describe, and then if you manage to finish the cereal first, the cereal flavor will be ingrained in the milk! Making it a sweet drink and last reward once you have finished it all.

Thanks.