Seeing as the rest of the Avengers showed up first and answered the question, the most I have to contribute to this is a Kurt Vonnegut quote that, while funny, I don't really agree with: "Here is a lesson in creative writing. First rule: Do not use semicolons. They are transvestite hermaphrodites representing absolutely nothing. All they do is show you've been to college."
I don't think Kurt put enough thought into this one. They could be a hermaphrodite that looks more male or more female, at which point the transvestite part really does matter. Though I'm also not entirely sure if there's any particular sex that hermaphrodites more closely resemble as a general rule. I mean, I know there's a particular situation in Salinas in the Dominican Republic, but that may not technically be the same sort of condition, even though those affected develop as girls until about 12.
Also, the college thing might be very useful as a way to change up a style. If a character's supposed to come across as more educated or snobby or something, perhaps their own writing or way of speaking includes semicolons.
Finally, be careful staring at writing too long. The more you think about how you spell words, the more difficult and counterintuitive it appears to be. If it's I before E, why is "weird" so weird?