Learning by...osmosis?

Osmosis is actually the movement of a solvent, such as water, through a semipermeable membrane (SPM) from an area of LOW solute concentration to an area of HIGHER concentration; the resulting concentrations are equal, but midway between the HIGHER and the LOWER. "Learning by osmosis" would actually result in LOWER or diluted content knowledge, assuming that the solute represents the information.
The actual metaphor should be DIFFUSION, in which the solute moves across the famous SPM from an area of HIGHER concentration to LOWER. The resulting concentrations are equal but the direction of movement is toward the "emptier" solution. Like a brain?
However, neither analogy is correct regarding the learning process. The actual metaphor is closer to FACILITATED DIFFUSION, in which the material moves down the concentration gradient using an enzyme or cell receptor and consuming energy, or ACTIVE TRANSPORT, in which a carrier protein moves the information consuming even more energy.
Either way, learning is not passive and requires energy!