With reusable cups I have observed a psychological barrier with myself. I was unwilling to use it when it felt "awkward" (i.e. I'm likely the only person asking

With reusable cups I have observed a psychological barrier with myself. I was unwilling to use it when it felt "awkward" (i.e. I'm likely the only person asking to use my own cup the whole day). However lately it became more common (I live in Germany), more shops offer discounts if you bring your own cup, more likely that the person in front of you also has a reusable cup.