The Buddha compared people to the lotus 

Some are very wise, with minimal defilement, ready to attain enlightenment whenever exposes to Dhamma, similar to the lotus flowers above the water readily bloom upon exposure to the sunlight. 

Some are wise, with little defilement, yet need more training to attain enlightenment, similar to the lotus flowers at the water surface will bloom on the next day. 

Some with fair amount of defilement, need more instructions and training to become wiser and be ready to attain enlightenment, similar to the lotus flowers under the water, waiting more time to grow above the water level to bloom during the successive days to follow. 

Some are full of defilement, with a dull mind, not possible to attain enlightenment, similar to the lotus flowers in the mud under the water, will be eaten by fishes and turtles.