Clarifying Statements: Helping to Explain

People often come to me for advice. They come up to me and ask one simple question: "Colon, can you help me explain something?" Being the nice piece of punctuation I am, I always respond positively. I offer to use my services to connect two statements, one of which clarifies another. Take note of the following examples:

Patrick was extremely disappointed in himself: he had received a bad grade on an essay he had written.

After a long weekend, we finally felt a wave of relief wash over us: the grammar project was finished!