George is a small and strong man, he is very impatient with Lennie.. Lennie has a discapacity as a large, strong, lumbering, simple-minded man who is usually unware of his actions and surrondings. His favorite thing to do is pet soft things.
Being migrant workers they drift betweeen towns looking for work to support themselves. Their goal is to be financially stable in order to own their own property and be heir own bosses. This goal is hard to acheive due to Lennies discapacity in the way. Also a stable wayof surviving.
Lennie cannot survive by himself due to his disability. This is why George looks after him. They dont get a very good job because of the boss. The boss also starts noticing how George does all the talking. So Georges struggle for survival is twice as hard as Lennies.