Why did Jonas ask to give him painful memories?

Jonas needs to store the memories of pain because as the novel suggests in rhetorical terms, Jonas' society was fully unaware and ignorant of common feelings. Thus, Jonas had to make sure that he understood what pain was in order to remember and carry on the Giver's sole purpose - the preservation of life and the aspects that go with it!

i think its because according to the giver it gives us wisdom and teaches us what pain is