If you take a hot dinner plate from the oven and burn your fingers, the flexor reflexes contract your arms but you don't want to drop the plate on the floor, so you balance the plate on the tips of your fingers till you can put the plate on the table. A Conditioned Reflex is not a true reflex in that we usually don't know the nerves involved. This is a type of learning, an association between a signal and a reward. In many ways our education builds up a series of conditioned reflexes in our nervous system. Fast learners require only a few trials for them to associate the signal and the reward.
Slow learners require many trials.
Some may never learn a given pattern.