Yep, you got it right. It used to come from "RTFA" (read the fucking article) years ago when people would ask questions in the comments that were clearly answered in the article, then eventually morphed to include FTFA (from the article) and just TFA.
Edit: just googled this to see if I was giving you wrong info also, and it looks like it came out of RTFM (read the fucking manual) for people in early Unix communities too.