This quote from page 153 shows how hard training is for Jonas. This also shows how much he cares and how he only expresses his emotions to the Giver at this time in the story.
"No one heard that twin cry, either! No one but my father!"(Page 153)
The quote from page 163 shows how Jonas mentally prepared himself for the journey and reassured himself that it would work.
"It would work. They would make it work" (Page 163)
When Jonas released the memories it effect others because these memories are very painful. The community will have a hard time dealing with gaining 1000's of years worth of memories at once.
"The memories had fallen behind him now, escaping from his protection to return to the people of his community."
When Jonas and Gabe were running from the planes the leaders of the community sent Jonas had to give Gabe the memory of snow to make them both cold so the heat sensors wouldn't pick up their body heat. This shows how determined Jonas was to save Gabe and free the memories.
Jonas' looks are unique because he is one of the few people in the community that have what they call "light eyes". The Giver has light eyes just like Jonas, as well as Gabe. The Giver and Jonas both became Receivers so there is a possibility
The job as the Receiver effected Jonas' whole life and flipped it upside down but he still pushed through. Jonas was very hard work and determined. Jonas' training was very painful but he pushed through because he had to, this made him very strong. He was also very brave for going on the journey and was determined to save Gabe. Jonas was put through so much and was able to handle so much at the young age of 12.