You are 14, so I will excuse the naivety. The year you were born is when I first used the microsoft computer. That is all it is, a computer. You are a human. The computer knows nothing, you know everything (you just don't think you do, but you do). Most books don't even follow rules like that anyway. I have read numerous books and not all of the sentences were complete sentences. Some were runons, some were fragments, some were one word. As long as the spelling is stellar, the vocabulary is rich, the character development is excellent and the scene descriptions are vivid, it doesn't matter whether the sentences are runons or fragments, that's for English class only.
Edit: your sentence is perfectly correct. It's not a fragment. What BOSFLASH said is absolutely incorrect because a semicolon separates independent clauses only. What comes after that semicolon of his is NOT an independent clause.