People who make little comments as you walk away are, imho, hoping you will confront them because they don't have what it takes to DO something to make you notice. They (and their words) are not worth your time, anymore than a little child saying you're fat, or in my case, "Mom! That woman is a man!"
I just smiled at the mom, btw.
Much of our struggle to transition is learning to ignore most comments, looks, etc. It's hard, because we've spent our lives being hyper-aware of how others perceive us, and the desire to "pass" as our designated gender is so ingrained...
For myself, when I realized I was "acting" when I presented as male and simply "being myself" when presenting female, my concern for how others perceived me went out the window.
I am presenting authentically, and if I don't meet with someone else's idea of how a woman should look like, sound like, or whatever...that's their problem.
Fwiw, my ex also said I live in a bubble, but as much as I choose to ignore other people's disapproval, she chose to notice every little slight, every glance, every eyebrow as criticism of my existence. She was just hurting that "her man" could be anything other than a man.