You get on the Bus. You spot a vacant seat, and rush to the seat to bag it.
Why does it feel so wet? Your friend suggests that it's only because it's cold.
But then..you realize, with horror, that the pleasant looking lady who vacated the seat for you lost control over her bladder before she left.

Believe me, this is a TRUE story courtesy of my friend Eunice.
Eunice agrees with me when I say that she should wear surgical gloves when she gets on the bus in case you want to hold on to those unsterile handles. According to her "You never know where people's hands have been". She's right.

Don't you ever check your desk, the floor, the seat itself before sitting down in the lecture theatre? I do. Call me paranoid, but honey I don't want no chewed gum sticking on my clothes, my boots brushing with someone's 'sick' and other icky things.

I'd rather go to the lecture theatre and on the bus wearing a space suit.