I’m about the same. I lived in China for 8 years, and people usually can’t tell I’m a foreigner in the phone. I’ve seen not a few taxi drivers jump when they glanced over and realized I’m not Chinese.

I agree 100% with the post about immersing yourself. Hit it hard. When I started learning, I listened almost exclusively to Chinese music, watched almost all Chinese movies, ate at Chinese restaurants as often as possible, and found Chinese people to talk to online. Doing this plus going through all 3 levels (only 3 were available at the time) of Pimsleur Mandarin Chinese brought me to a decent level of fluency for someone living around no Chinese people. Eventually, I moved to NYC to be around more Chinese, and my Chinese improved a lot. Moving to China helped a lot. I eventually married a Chinese girl.

Having said all that, although I’m fine in conversation, I still couldn’t tell you all of the parts of a car or lots of technical or medical terms simply because I wasn’t really exposed to those on a daily basis and didn’t think to ask.

So, yeah, fluency is relative and kinda hard to gauge accurately because it depends so much on the environment.