I'm simply comfortable with my vocabulary being at the level it's at.
I would never use a word out of a Thesaurus unless it was already
in my vocabulary. (And I suspect this is true of others who use the Thesaurus to remind them of words they can't lay hands on at the moment).
I sometimes have trouble remembering
names that I should know perfectly well -- then a day or two later they'll surface in my mind, just bang! out of nowhere since I'm not thinking about anything that could possibly relate. If it's a name that my husband and I were trying to think of together, I'll shout it out, right in the middle of something else. Fortunately, he makes the connection with our previous conversation, and doesn't think I'm losing my mind. Once, it took me several days to remember the name of a show that I watch
every single episode during its season. As middle age helplessly plummets toward old age, this is how the mind increasingly works (or ... well, refuses to work when you want it to).
Anyway, when I'm writing, I'm not going to wait that many days to grab hold of a word that I already know, so out comes the Thesaurus. Which is quite a different thing than using it to look like I have a better vocabulary than I actually do.
On the other hand, I'm always happy to expand my vocabulary through reading and familiarizing myself with new words. I'm
comfortable with my vocabulary at the level it's at, but I wouldn't say I'm satisfied, because I always want more.