I might disagree. Though I am very introverted I experienced how much Chinese I could learn and have as actively known vocabulary in just 3 weeks being in China

I might disagree. Though I am very introverted I experienced how much Chinese I could learn and have as actively known vocabulary in just 3 weeks being in China travelling. Simply because I needed it. And I did have to force myself to speak in some situations to immerse myself. You could for example go into a modern shop and buy food silently, or you could get something great from a streetfood vendor, asking prices, understanding answers, telling them what you want to buy, possibly negotiating the price a little. Or you could walk around for an hour trying to find a place, or ask a local and get there in a few minutes.