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.
To an extent that I look up the same word after 10 pages or so.