A lesson in thinking before you speak:

A few years back I was at a friends house, staying the night. His mother's a social worker (or something similar) and often had some pretty weird people round. The next morning there was some woman I didn't know sat in the lounge, nothing unusual so I went downstairs to the kitchen.

We sat round the table, read the 'papers, and chatted while his mother made toast. She shouted upstairs that she was making breakfast. No one came down for some time, which I thought was slightly odd, then the door opened and the 'mystery' woman crawled into the room on all fours. Actually crawling, and dragging her legs behind her.

Naturally I was surprised at this. So I disengaged my brain and said:

"Why don't you just get up and walk?"

"Because I have MS."