"Going to the concert last night was one of those historical occasions," Mattie enthused.
Really? I'd hardly call last night historical. When you use historical, you are referring to something significant in the past. If you use historic (as Mattie should have), you mean important to Mattie; it may not be important to you.
Read the following two sentences.
1. To be old enough to vote for the first time was a historic moment for me. This is correct because it refers to an important moment in my life. Your first opportunity to vote may not have been of great consequence to you.
2. It was a boring lecture about the historical romance of Napoleon and Josephine. This is correct because the romance was an important event in the past. It's a recorded romance, so it's not just one person's perspective.
How can you remember the difference? This is one of the terms I've struggled with, so I'll tell you how I distinguish them. When I use the word historic, it's a subjective term. That is, I make a judgment or decision about the importance of an event. Historical refers to the past and is a neutral word.
If it's historic, it's important to me;
if it's historical, it means an important event in the past.