While that may be true, you also put them in places that should have a comma, but you want more pause; this is why boiling it down to a single aphorism is difficult.
For example, I’ve read most of the comments in this thread, as well as the Oatmeal info-comic that someone linked, and I still don’t know with certainty the semicolon I used above is grammatically appropriate.
Basically you use them at points where you’d usually put a period, but you don’t want to add as much of a pause.
ETA:
For example
could also be written as
but it wouldn’t sound as nice.
While that may be true, you also put them in places that should have a comma, but you want more pause; this is why boiling it down to a single aphorism is difficult.
For example, I’ve read most of the comments in this thread, as well as the Oatmeal info-comic that someone linked, and I still don’t know with certainty the semicolon I used above is grammatically appropriate.