Ask a pot smoker about the difference in potency from one marijuana strain to the next, and you’ll get an earful. Or ask a coffee grower: Arabica beans grown in one part of Ethiopia can have six times as much caffeine as those grown in another part of the country. And depending on how they’re ground and brewed, the same beans can yield different caffeine amounts.
Quote Source: https://www.nationalgeographic.com/magazine/article/ancient-chines-remedies-changing-modern-medicine
Thus that's how one can begin to unpack Mencius in order to understand how he teaches us about learning...
Take barley for comparison. If you broadcast the grains and rake the soil over them, and if the soil and planting times are comparable for all, they will all shoot up and ripen by the summer solstice. If there are differences it is because of the differences in the fertility of the soil, or in the nourishment of rain and dew, or in the labor of the farmer…. why would we suspect it to be any different with people?
Quote Source: https://1000wordphilosophy.com/2018/04/10/mengzis-moral-psychology-part-2-the-cultivation-analogy/