Repetitious, perhaps? Recurrent? Neither seem like an exact fit.
We do it bass-ackwards for some reason; I don't know why. That and everything else.
Parentheses are my favorite punctuation. I like to use them (if you couldn't tell) to interject fragments (and occasionally complete sentences) into my speech to add (semi-)relevant extra information.
I do try and keep them out of my papers, though.