I'm going to try to avoid having mentally challenged people sit next to me on the bus
Why avoid sitting next to them.
It is an uncomfortable situation, when a mentally challenged person acts weird in front of you.
Sometimes they can do things that seem weird but they can't help it. You shouldn't be prejudice against them since not all of them act the same way.
They shouldn't be allowed on the bus. They are a pain in the ass and they act retarded.
You need to be more respectful of mentally handicapped people. There are certain actions that they have no control over. If you are going to act this way towards them, do not take the bus yourself.