In The Giver, how does Jonas emotionally and physically go against the community and sameness?

When Jonas starts receiving memories from the Giver, he learns about all of the different sacrifices the community made in order to live according to Sameness. Many of these sacrifices Jonas could accept, such as Climate Control, which is discussed in chapter 11. The community had to give up snow and sunshine in order to be able to control the agricultural periods and eliminate hunger. That's understandable for a twelve year-old boy; but, what is difficult to swallow for Jonas is living without color and preferential choice. Add these sacrifices to Jonas learning that the word release means death and the scales are tipped. Once Jonas sees his father kill a little baby in the name of Sameness, Jonas emotionally revolts and wants to go against the community. 

It is this emotional revolt inside Jonas that motivates him to also physically revolt. The Giver happens to have a plan:

"If you get away if you get beyond, if you get to Elsewhere, it will mean that the community has to bear the burden themselves, of the memories you had been holding for them" (156).

Therefore, Jonas must physically leave and cross over into Elsewhere in order for the memories to flood back into the community. Once Jonas has physically removed himself, and the memories enter the minds of the people, they will certainly feel things emotionally that they have never felt before. In a way, it's almost like he is attacking them emotionally because they will feel love and pain, happiness and sadness, joy and depression all at once. Not only that, they will experience the physical pain that comes with the memories as well. For instance, Jonas physically felt things like a broken leg and sunburns when he received memories.  That means the community would experience these things all at once, which could cause chaos. The Giver explains as follows:

"I have to stay here. . . If I go with you, and together we take away all their protection from the memories, Jonas, the community will be left with no one to help them. They'll be thrown into chaos. They'll destroy themselves. I can't go" (156).

It's a good thing the Giver decides to stay in order to help the people because the memories could attack them both physically and emotionally all at once as Jonas crosses over into Elsewhere.