your not an idiot! but it does take some practice to cut.. itook a basics class when i first started quilting, and learned alot..
here are some U-Tube shorts on cutting with a rotary cutter, i don't know if it will help, but worth a shot, since we can't be with you!
http://video.google.com/videosearch?...=com.microsoft:en-US&q=how+to+cut+fabric+with+a+rotary+cutter+site:yout ube.com&um=1&ie=UTF-8&ei=ZC-RS-LaDoHQM7j99PgM&sa=X&oi=video_result_group&ct=title&resnum=4&ved=0CDIQqwQwAw#