You mean they don't drink it? I used to love the leftover milk from my Cinnamon Grahams (still do so I suppose I confess to still eating Cinnamon Grahams occasionally).
I find the actual cereal too sweet for my ageing palette - the milk is the best bit. No idea why they don't down it afterwards, like I used to with Ricicles...
I've been using the leftover milk from my kids cinnamon crunch cereal to put in my coffee.