A few days ago, I noticed a fox standing outside this building. The fox was so deep in thought, it didn't hear me sneak up behind him and was startled when I said hello.
Today, as I was walking home, I noticed a man fiddling on his mobile phone. He was so engrossed in what he was doing, he didn't hear me approaching. When he looked up and saw me he was startled.
My mother has told me I've startled her a few times. She reckons I walk like a cat. That's probably why I can sneak up on man and fox.:-)
Related articles: No So Sly, Fox!; Making Myself Invisible