Have you ever read an amazing mystery novel, and solved the mystery yourself before finishing the book? If so, you were able to put critical and analytical thinking to work by taking note of all the details provided and sorting them out to determine "whodunnit". That same ability to analyze details also comes in handy when it comes to critiquing the plot; determining whether it was a well-written piece, if the characters were properly developed, if the storyline ran smoothly, etc. Should you ever have an opportunity to discuss the book with others, you'll be able to state your opinions clearly, as you've taken the time to really consider all the aspects involved.