Memory: Pain perception

Pain, in any form,  is one of the most common chief complaints presented by patients visiting hospitals.
Specific forms of pain are likely to indicate certain diseases; therefore, description of how the pain feels and how much discomfort it causes are of great importance.

In medical record writing, pain is measured by a scale of 1 to 10, which provides subjective observation by the patient. I have not undergone any major operation or experience any sorts of deep pain, so it's not likely I can relate to how the patients feel.

In his book, Thinking, fast and slow, Daniel Kahneman proposed that, from pp.379-pp.381,
there are two principal rules that affects how patients perceive the pain.

He designed an experiment that two patients undergoing a painful colonoscopy. Because the data was collected in the early 1990s, it was performed without administration of anesthetics. 

Who do you think suffers more ?

Consider two rules:

1. Peak-end rule.

2. Duration neglect.

For 1., both groups have the highest score at 8, but Red ended with 7, Blue ended with 1, thus giving a mean value of  7.5 and 4.5 respectively.

For 2. It's evident that Blue sustains longer duration.

However, the answer is that patients blue feels LESS pain despite undergoing longer duration.
Conclusion is that what matters the most is our memory in the end that affects how we perceive and feel about the event we have been through.
(I'm jumping a little a bit but that's basically what the author expresses..)