Jonas transmits memories to Gabriel, Meaning that He cares for Gabe. He may have lost those memories, but as you may have notice, people who transmit memories to another show some well, love towards each other, Rosemary being the Giver's daughter, and Jonas, who get along quite well, both receive memories from the Giver.
Another example of this theory, is Jonas giving memories to Gabriel, maybe because Jonas wants Gabriel to experience these good feelings , because Jonas Cares for Gabe. Making a connection here, but if anybody reads the Harry Potter series, (if you haven't, you seriously should) you'll find a lot of comments about how love is really important. What I'm trying to get through, is that Jonas has taken the choice of love, he can love.
Another Thing that Jonas Had choose was the eating of the pill that he needed to take at the beginning of each day, was maybe because Jonas realized ( although it did not say in the book) that he wanted love, but the pills were stopping it.
