Semicolons: The Grammatical Bane of my Existence.

I’ve got a confession; it’s been weighing heavy on my soul for years now:
I don’t know how to work a semicolon! Really. Despite the fact I just used one in the above sentence, I absolutely do not know how to use a semicolon. It’s a problem that’s been plaguing me since I was a junior in high school. My former English teacher, a complete hard-ass, was going over the proper uses of a semi-colon. It took the entire class, and since I was/am such a terrible student, I totally spaced out the entire time. Sorta sad, I know.
So, semicolons. We as students know that a semi-colon is properly used to join two related ideas when there are no conjunctions, specifically and, but, or, nor, for, so, and yet. For example:

I like to eat pie; I am not a fan of cherry pie.
as opposed to
I like to eat pie, but I am not a fan of cherry pie.

That’s not the best example but I’ve got pie on the mind.

Also, a semicolon can be used conjoining two clauses when one begins with a proper noun, such as I, he, she, him, her, you, a name, or it. For example:

I like the blister that forms on my right thumb when I've been playing guitar a lot; it makes me feel cool.
as opposed to
I like the blister that forms on my right thumb when I’ve been playing guitar a lot, because it makes me feel cool.