One of the high points of this chapter is the idea of friendship. As Slim and George are talking, Slim mentions that he almost never sees people travel together. So when he see that George and Lennie are together, he pauses for a bit. This idea of friendship is one of the delights of life. Anyone who ever had friends is able to relate to this.
Second, in this chapter George also recounts to Slim that Lennie grabbed a girl's dress, because he liked to touch soft fabrics. The girl mistook this for something violent. When others found out, rumor got out that Lennie sought to rape her or something to this effect. So both George and Lennie had to run away. Things like this also happen in real life. People miscommunicate and people jump to wrong conclusions with disastrous effects and consequences.
Finally, Curley, feeling insecure about his position in the farm, lashes out against Lennie and picks a fight. Unfortunately for Curley, he messed with the wrong man. Lennie crushed Curley's hand. Again there is something realistic about this because people fight, people are insecure, and people get hurt when things like this happen.