I read a book, it was called something like happiness for pessimists or something like that.

In that book the author was asked by a famous psychologist to ride the metro. And exclaim at every stop the name of the station loudly.

He was all nervous when the first station came. But he called out. Some people glanced at him a bit. But the reality was nobody cared. So after that it became easier and easier.
Would I be nervous when I had to do it? Hell yes.
Would I care if I was a passenger and somebody else did it? Nope.

Maybe it would be a start for a conversation even.