How important is patience in buddhism?

I've heard that patience has a big place in Buddhism. It is especially very important for monks. I can think two ways of patience. 1. When we get angry, we have to have patience to avoid bad consequences. 2. Most of practises in buddhism don't give us a result immediately. So we have to have patience to see a result. (Delayed gratification) What are the teachings of the Buddha about patience ? I can think of case 1. But I want to know about case 2. If a person is unable to delay gratification (not only in Buddhist practises), does it means that the person has excessive clinging? (Is it a characteristic of that kind of person ?)