You've been thinking too much...

Casein absorption: Almost 80% of the protein found in milk is in the phosphorus-containing form known as casein – a complete protein. Casein is hydrophobic (literally “scared of water”) and so it is not soluble in water but instead appears in milk as a suspension – and for this reason it is also called “Micellar Casein” (separated without the use of chemicals). The human body, however, processes casein a little uniquely. Unlike whey (another dairy protein) which the body can absorb very fast, Micellar Casein takes a while to be absorbed into the cells and so its processing is not a high priority task for the body. Milk consumed during the day will still slowly get you the protein, but when consumed at night it gives the body the best chance of maximum absorption.

Source: http://www.fitnessmantra.info/2007/02/15/5...before-bedtime/

Regards, Joey