Reminiscence, Primacy and Recency Effects are processes that retard Trace Decay.
There are other important processes that mitigate against the forgetting curve. One is called the Reminiscence Effect, which occurs anywhere from seconds to minutes and longer after learning.
It is a brief spike in the curve in which the recall of learned material actually increases. This is believed to be a result of a consolidation process, which involves reinforcement and integration of the new material with data already stored. Others include the Primacy and Recency Effects where you retain the first and last bits of data learned in a series.
Taken together (i.e., 1. Reminiscence, and 2. The Primacy and Recency Effects) the wisdom of many short breaks in learning becomes clearly evident!
They provide time for the first process to occur, and proliferate the opportunities for the second to take place.