They've learned enough about recycling to know that participation is good, contamination is bad.
But despite having (in my friend's case a Ph.D) years of exposure to our advice, lectures, and examples, they are like an Expat who cannot speak our language. "What about THIS?" drew a #metoo laugh when I described my live in partner's method of recycling. In her defense, she remembers where she puts her keys, I need to ask her for a reminder.