George is a man who is trying to do the right thing. He is really in a parental role for Lennie, who has the emotional and intellectual capacity of a six year old. George frequently vents his frustrations about how easy his life could be without having to take care of Lennie:
"If I was alone I could live so easy. I could go get a job an' work, an' no trouble. No mess at all, and when the end of the month come I could take my fifty bucks and go into town and get whatever I want...."
George however made a promise to Aunt Clara that he would take care of Lennie. On a deeper level, George loves Lennie. George is a very sympathetic character.