I always immediately think Young Adult, but some people just don't seem to register the abbreviation at all for some reason. I was chatting about YA to one of my co-workers, and I called it 'YA', rather than 'teenage books' or 'young adult', and she immediately went What? She'd seriously never heard it called that. How can you work at a bookshop selling YA for years and not notice?
Then again, maybe I shouldn't be using it in conversation. Maybe it makes me sound too much like I'm using acronyms for the sake of using acronyms.
Oh, the chronic overthinking I do about everything I say...