I love this nongrammatical/idiomatic use of parentheses actually. Language is a tool, and its rules can be just as powerful when violated as when upheld.
In this case they convey a subtext you can’t get as gracefully by being a slave to syntax— that the author hoped the post would be about how they did achieve success, but that didn’t happen, forcing the parenthetical qualifier. I don’t think another treatment would express that quite as well; you can almost feel the wince.
In this case they convey a subtext you can’t get as gracefully by being a slave to syntax— that the author hoped the post would be about how they did achieve success, but that didn’t happen, forcing the parenthetical qualifier. I don’t think another treatment would express that quite as well; you can almost feel the wince.