Universal theme: people dream but have to go through obstacles to achieve this dream.
"You ... an' me. Ever'body gonna be nice to you. Ain't gonna be no more trouble. Nobody gonna hurt nobody nor steal from 'em."
In of mice and men lennie and George's dream was destroyed because lennie got in trouble, And couldn't handle his strength. This was the obstacle they had to face to get to their dreams but in the end it was destroyed.
"It ain't the right kind of life for a woman. Her upper lip raised showing her teeth. How do you know? How can you tell? She said."
Elisa's dream was to travel like men because woman weren't aloud to do what men do. So she lost her dream because of woman's rights. Her obstacle was woman right.
"Then they tied him up and took him to jail."
Tularecitos dream was to be with his kind of people, the gnomes. This dream was destroyed because he killed a man. His obstacles were getting to his kind by going in the rabbit holes.
In the real world a dream could be gained or lost but to gain this dream you have to go through obstacles. Say your dream is to become a professional player for whatever sport you have to go through the obstacles to get better and achieve this. If you don't you loose this dream.