I laughed at work when this fat lady using our motorized shopping cart got stuck in the doorway and started crying
That is not a nice thing for you to do. Why would you laugh at this woman who is in an embarrassing situation?
I thought she was joking and she was making fun of me.
If you see someone stuck it is expected that you help them. You would wish for someone to help you if you were in need.
It's not like I didn't do anything. I helped her out of the cart.
I'm glad you finally helped her despite laughing at her. It is a good thing to try and help someone that can't help themselves. Hopefully next time you might feel a little bit of sympathy instead.