Just out of curiosity, why would you want to sneak up on Picasso and yell "Boo" in the first place? Naturally, it would jump, so would you! Some people and some animals are just born a little more nervous than others. A good way to enforce the feeling of fear is to continue scaring a person or pet on purpose. All kittens right up to a year are going to be wild little Indians. There must be 1,000 things in any given room that are possible things to play with or an adventure to have whether it's playing with a shoelace or climbing the drapes, or --- climbing the Christmas tree! Picasso is a beauty. Congratulations on getting your first cat.