In what ways does Lennie fail to meet George's needs in Of Mice and Men ?

Based on the information that the character of George verbalizes throughout the novella, it is safe to say that George's needs are the following:

• Stability- In more than one occasion we hear George complain about having to move from one place to another because of Lennie's issues. It is impossible to blame him. He has had to run from town to town all because of transgressions that he had not even committed. It is frustrating to him, and with good reason, to never find a place to stay and flourish. It is very hard to make a plan, and carry it on, where there is no solid ground upon which to base it.

Steinbeck - Of Mice and Men

I could get along so easy and so nice if I didn’t have you on my tail.

• Compassion- George complains a lot in the novel, but he has every reason to do so. He does not ask for anything for himself and he always keeps Lennie by his side. Yet, even in his conversations with Slim, there is a degree of vulnerability that betrays his want for the world to understand and appreciate what he goes through with Lennie on a daily basis. 

Therefore, it is very hard to be George. You have to be compassionate and full of patience, accepting, flexible, and willing to sacrifice.