After starting Ulysses recently, I am noticing that my speaking, writing and expressing (as compared to reading) vocabulary is severely lacking. Now Ulysses might not be the best book to draw this conclusion from, but I have other reasons too.
Consider this really basic line from the book:
His hands plunged and rummaged in his trunk while he called for a clean handkerchief.
I don't feel like any other alternative for 'plunged' and 'rummaged' would do. But I don't remember actually using these words anywhere till now, even though I have expressed sentences in similar, rummaging, contexts. Most of the time I just end up fitting in an overloaded and overused word or phrase.
In technical writing, a lot of focus on keeping things simple and avoiding fancy words has diluted my opinion of what an extensive vocabulary can help communicate. This is not to say that I should start using 10 dollar words more often, but to actively look for better words whenever possible.
Facing new words the classical way, I usually miss out on usage and so they only remain in my reading vocabulary's most temporary corners 1. To focus more on self usage, I should setup some sort of spaced repetition system that makes me use new words and help compare with other usage patterns across books, articles from my library.
Footnotes:
To an extent that I look up the same word after 10 pages or so.