Ever since someone presumably told me how to feel about parenthesis, I've always felt that parenthesis were optional reading; you could skip em, if you wanted to. To this day!
(I learned about it at the same time we read the story 'Dragon Soup' in the 3rd grade - or was it the first grade? The 3rd grade doesn't seem as cheery an environment as the first, which seems a lot more appropriate of a place to have been reading Dragon Soup, but oh well. Whichever grade it was, I remember skipping ahead in our reader to Dragon Soup, before our class got there; one of the last paragraphs, I kept imagining for some reason that when we finally were reading in class, that my dad would read it - but when the time came (we were going in a circle, reading a paragraph each or something), despite my dad (who volunteered in my class and my sister's class once a week or something) being in the same circle I was in - the reader of that paragraph turned out to be me! Come to think of it, maybe I learned about paragraphs beforehand, and I can't shake my memory connecting Dragon Soup and the Optional Paragraphs Rule, because that one special paragraph had a parenthesis in it - but I can't remember if it was an excellent or poor use of parenthesis. I think it went "So the king had dragon soup (the chef had used beef instead)...", and I can't remember the rest. I think someone was reassuring the dragon, though.
'Amazing Grace' always reminds me of Parenthesis, too. I mean, the parenthecised part is worked right into the tempo of the music - so how could it be optional?
This is just one of those early ideas I picked up, that I never quite shook off - like the one that the first 6 years of my life (from 1985-1990) were all 1991. The evidence I have that I thought this, is looking at a magazine (Child's Life, I think it was) dated 1989, and thinking "I was never around in the 1980's...", despite, y'know, being born then & all. Once I figured it out, I considered going into denial, to keep on thinking it was 1991 - but I figured it'd be too hard to be in denial about that, so I decided not to.)