Well, you may or may not outgrow your need for it, but a lot of people outgrow their ability to digest it without a lot of discomfort. According to the article, one of the reasons for the milk sales decline is that the population has a lower percentage of children in it. I would add that it may also be that because of changing demographics, a growing percentage of children are lactose intolerant.
Lactose intolerance develops after the age of weaning in the majority of people worldwide. In fact, the ability to digest milk as an adult without experiencing any negative symptoms (gas, bloating, etc.) is the exception rather than the rule:
The frequency of decreased lactase activity ranges from 5% in northern Europe through 71% for Sicily to more than 90% in some African and Asian countries. This distribution is now thought to have been caused by recent natural selection favoring lactase persistant individuals in cultures that rely on dairy products. While it was first thought that this would mean that populations in Europe, India, and Africa had high frequencies of lactase persistence because of a particular mutation, it has now been shown that lactase persistence is caused by several independently occurring mutations.
As for me—well, I detest milk, and have ever since I was a very small child. You’d have to hold a gun to my head to get me to drink it. At some point in early adulthood, a somewhat sadistic doctor ordered a test during which I had to drink twelve ounces of lactose (milk sugar, the stuff lactose intolerant people can’t digest) on an empty stomach, and he then measured my rise in blood sugar afterward for several hours. There was no rise at all, meaning that I’m one of those people who lacks all ability to digest lactose (some people have a partial inability).
I will spare you a description of how I felt during the hours after I swilled down that abominable stuff. Let’s just say it wasn’t pretty.
So, are you a milk drinker?