I wonder why I always get sleepy people sitting next to me on the bus. I don't remember having declared my shoulder to be a public pillow to rest their sleepy heads on! I had to nudge one idiot very hard today as he kept leaning on my shoulder. One of these days I'm just gonna get up abruptly and see if those sleepy bums fall over.
Sometimes in a conversation I tend to go blank once in a while. It has nothing to do with the other person. I just switch off for a moment or two. This exasperates me.