Goofs

(at around 1h 10 mins) After Walter and his son have found the buried skeleton only to return with the police to find it gone, they are met by his wife, whose hands are clean. However as they drive home Walter notices her hands are very dirty.

(at around 1h 4 mins) When Agatha enters the Nathaniel Institute, it is dark outside, but when we see her again in the doctor's office, bright light is shining through the windows. When she leaves again it is dark.

(at around 6 mins) When Walter is first trying to catch Ned (the dog) behind the Chinese restaurant, the way that his stick-thing is positioned changes from the shots in front and behind him.

(at around 9 mins) When Agatha is proceeding to the bookstore, the van in the street behind her disappears between shots.

(at around 44 mins) LED clocks don't click when switching numbers.

In real numerology, numbers are added together to form a single digit number that might have significance. The sum should never exceed 9, except for the "master" numbers 11 and 22. This is in accordance to the nine personality types, the nine planets in the solar system, and many other things. For example, Walter's room at the asylum was 318. When calculated in the movie it is suppose to equal 23, 31-8=23. However in real numerology the number would be added as 3+1+8, equaling 12. The sum would then be added again to create a single digit, 1+2 = 3. 3 would be the significant number here, and there are many sources on the Internet or in various numerology books that would define what significance that number would hold for the individual. As another example, the address of the bookstore would have more credibility as their sum does equal 23 (5+9+9=23). But another step would need to be taken to convert the sum into a single digit (2+3 = 5). Finally, birthdays and other notable dates in numerology are always factored with the year. Following the formula of February 3 (2/3 = 23) would be inaccurate. But December 12, 1975 (12/12/1975 = 1+2+1+2+1+9+7+5 = 28 = 2+8 = 10 = 1+0 = 1. Therefore, for a person born on this date, the number 1 should be the most significant.

(at around 41 mins) In the film, Walter Sparrow claims that the serial killer Ted Bundy died on January 23. Ted Bundy was actually executed on January 24, 1989. However, he was pronounced dead at 7:16 am (7+16=23).

(at around 37 mins) A segment in the opening credits states that the Mayans believed the world would end on December 23, 2012, while in the film, Danny Huston's character reads that the Mayans believed that the world would end on December 12, 2012. In actuality, the Mayans did not believe the world would end in December 2012; they believed a new world would be created. (The date of this is still widely disputed as well, with some sources placing the date as December 21, 2012.)

(at around 46 mins) When he opens the book to read chapter 21, he is on one of the early chapters, instead of closer to the end of the book. In contrast, at around 51 mins, when he reads chapter 22, he is clearly on the last pages, as expected.

When Walther uncovers Agatha and she is dead in his nightmare, she was clearly breathing just a moment before. Her eyelashes also move even though she is supposed to be dead.

Sex shown in chapter 21 is obviously simulated and the woman is just humping a man even though it's made to look like they are having sex.

(at around 1h 1 min) When Walter Sparrow enters in the post office while Dr. Sirius Leary is opening the boxes, we can clearly see sheets of Neutral Density filters placed on the windows behind Walter Sparrow.

(at around 32 mins) In the movie, Walter Sparrow was turning 32 and their son is aged 13/14, but Walter said that he met her wife when he was 23; how could their son be 13/14?