Lennie would tend to the rabbits whilst George looked after the technical side. This very dream shows both their weaknesses, as they both would stop at nothing to get it.
Later in the book Candy over hears George and Lennie talking about the dream. For the first time in his life he wants to be apart of something and offers to pay most of the price for the farm. After this moment the whole idea becomes more realistic and George and Lennie begin to make further plans. This means they will be together and will not be lonely any longer.
However this falls apart when Lennie kills Curley's wife and George in turn has to kill Lennie. It all falls apart for both Candy and George, as they both know it's not going to happen without Lennie. This makes them bitter, as they both will become lonely again.
Lennie's strength gets him into trouble because when Curley tries to hit Lennie, George orders him to hit back. As he does so he grabs Curley's wrist and breaks all the bones in his hand. He is so remorseful and scared for what he has done he panics and doesn't let go of his hand. He has to be physically pulled away from Curley by Whit, Candy and George. While Slim sees to Curley.
"Curley's fist was swining when Lennie reached for it. The next minute Curley was flopping like a fish on a line and his closed fist was lost in Lennie's big hand. George ran down the room.".
"Leggo of him, Lennie.".
(91).
This relates to the question because Curley is jealous of George and Lennie's relationship because he's lonely so he lashes out at Lennie so he can try and spoil this.
George and Lennie are close friends and crave each other's attention and approval. .
"Whatta you want?".
"I was foolin', George. I don't want no ketchup. I wouldn't eat no ketchup if it was right here beside me.".
(30).
George respects Lennie and Lennie is extremely respectful to George. George thinks Lennie is a good person at heart and doesn't mean to do anything wrong but in the end he has no choice to save Lennie and does the only decent thing.