So why does all this cell membrane lock/tunnel or permeation matter?
Because on our planet today, there are two (2) basic sizes of water particles or H2O molecules.
The first and most abundant is one micron in size. About 97% of the water we drink, that rains on us, that is on the surface of the Earth as well as under the surface of the Earth is one micron in size which is a large-sized H2O molecule or particle. As a visual you may want to imagine a basketball.