It's because it looks like I have some physical characteristics similar to people with Down syndrome. When I was younger I was also very shy and quiet because of bullying, emotional neglect and trauma (civil war). As a young child I was very outgoing and talkative but these incidents turned me into a grey mouse who would never in her life dare to talk to an adult unless she was asked. Then I replied with one short sentence. I was like this until my uni years, maybe until age 23-25. It's been only recently that I'm able to talk to people like we are equal and I got more relaxed and can even joke with strangers.

Most people don't think I'm disabled ( or they don't say anything), because I serve about 150 customers a day and incidents like this happen once or twice a year so it's not a high percentage of people statistically. I also get called names by teenagers in the street (every few months on average), but they usually call me Chinese or cross-eyed or fat. I'm used to that, it's just a part of my life. It used to be almost daily when I was a child, so it's actually "improved" now.
I ignore it and try to forget immediately. But I'll tell you every time it stabs me in the heart. I just can't think about it because I'd lose my mind.

I've had 4 surgeries and this is the best they can do.