Dark humor is like an extra chromosome Not everyone gets it, but if you do you're special
Don't you think people will be upset about this joke about mentally disabled people?
Naa don't you worry, a little retard isn't going to tell me what to post.
While it was acceptable for a long time to consider disabled people special, it has been a while where people with disabilities are not considered in those terms. There are more than just their disabilities just like you are more than just one thing. It would be good to learn more about disabilities so that you can  understand them better.