Users create this software themselves and often overlook how important it is. In some types of embedded systems, the application software and the operating system software may be indistinguishable to the user, as in the case of software used to control a VCR, DVD player or Microwave Oven.
You can jam milk through pretty small holes with force like that. Before homogenization, fat globules range in size from 1-10 microns (a micron = ~0.00004 inch). After, the size range is reduced to 0.2-2 microns.
By comparison, between 2011 and 2012, unregulated milk has increased from 14% to 19% of the total US milk supply. Dairy has changed materially over the last 50 years. Consumer eating habits have significantly changed. Per capita fluid milk consumption has dropped by 50% since 1945.