How am I insulting their intelligence?

When I was younger I was unbelievably hot-headed. So after so many trial an errors in my life i figured I should try to become at least mildly intelligent. So I boned up on my reading. Now I don't have the largest of vocabularies. But now when ever hit on a girl she tells me to stop using such big words. Since when is platonic or germaine a big word. I mean when I hear a word I'm unfamiliar with I listen for a context clue. I learned that in fourth grade for god sake. An it's not like I went to a private school I went to public my entire life. I even racked up a truancy record because of how many days I missed. Now of course I don't say this out loud. But Im thinking it, Also I tried to speak with a "smaller" vocab. But then I actually forgot a-lot of words.