Vocabulary.
I have approximately 9 years of post high school education, and can read with comprehension at a fairly high level. However, my daily vocabulary is not that broad. It's difficult for me to recall unfamiliar words on the fly. When I listen to podcasters, I'm always surprised by their verbal depth and breadth.
Is this your experience as well?
Yes this is my experience as well. I read a lot, have no problems with comprehension, but can’t get the words out of my mouth! I’ve always been this way.