Lennie wanted to live on a farm with George and have all sorts of animals. The one thing that was most important to him was rabbits. Lennie's maturity level played a major role on how much he liked rabbits. Lennie literally had the mind of a three year old. Just like the poem "To a Mouse" by Robert Burns, Lennie and George wanted to build a house and live in it, until something got in their way and ruined it. They were going to have all sorts of animals. Including puppies, cows, chickens, rabbets, etc. All Lennie ever wanted was to have a future with George.
Lennie's dream was ruined because he kept doing horrible things, to make George highly disappointed in him . The first thing that he did was he killed a puppy that was given to him by one of the ranch workers. After that tragedy, Lennie really didn't mean it, but he killed Curley's Wife. Curley was the bosses son and one of the most unpleasant people on the farm. When he killed Curley's Wife, that was the end of it for him. Curly was mad because he killed his wife, so him and his men went to hunt him down. Before Curly and his men could find Lennie and kill him, George had already found him. Lennie was explaining to him, he didn't mean to do it. George told him it was