<human>: That happened to me about 5 years ago.
I was in a train full of people. In the area in front of the doors, where there is almost no handles to hold on there was a crowd of 5-8 people. Right in the middle was a cute girl 18-22 years old. She was handicapped and walked on two crutches (I dont know how you call it, when the legs are a bit crooked, almost like that guy from South Park).
The train slowly stops, and in the moment where people were slowly tilting I see her panicky look. I notice she is not holding on anything (her hands were busy). A second later the train stops and she looks right in my eyes silently asking for help. I dont react, she falls to the ground. Get helped to get up. She wasn't injured, but was very desperate and confused, trying to smile and repeating she is OK.
I had enough time to move forward and catch her, but i didn't.
The reason was, I am also a bit handicapped. Not much. 
One my leg is 15 cm shorter then the other one(I was born like this). I wear the prostheses, so you cant actually see it if you dont look closely. Other then that i cant run and limp a bit.
My whole life I was trying to hide it and be like others. Never asked for help, never tried to use any benefits of being handicapped (like discounts etc), never address my leg and tell my friends to walk slowly. In that moment I thought she also didnt want to get any attention to her legs and ask for special help. 
After thinking about this case for many years I still feel bitter. Now I understand not everyone can be strong.
As for her, I guess she think I am just another arrogant asshole.

Condense the text into a few key points
<bot>: Didn't help a handicapped girl because I am also handicapped and  expected her to act as strong and independent as me.