Group A and B each had colonoscopies and recorded their pain levels throughout the procedure. While Group B experienced less total pain, they reported that they suffered more pain than Group A. This is because people tend to remember peak pain levels and the ending experience more than total pain. Both groups peaked at the same pain levels but Group A's procedure ended less painfully, so they recalled it as less painful overall. This phenomenon is known as peak-end bias in how people evaluate painful experiences.