Ha, ha, ha... I'm only laughing cause the same sort of thing happens to me - just ignore it, refocus on what you're doing and carry on. Meditation really helps train the mind to deal with this.
When I try to visualize exercises given at the start of NEW, I find that my mind likes to play tricks on me. Sometimes it tries to put something scary into the fantasy, such as a monster running past my vision quickly when taking a walk in the forest. Is this a commen thing for beginners and does it go away with more practise and development?
-Steve-
Step outside the square you live in.