People’s thoughts about the letter change from skepticism to realization as Jamal tracks the coordinates to the old house. Initially, folks dismiss the letter as just another one of Big Mac’s pranks, laughing it off and attributing it to his playful nature. However, their laughter turns to silence and concern when they learn that Jamal has discovered a real location connected to the letter, which indicates that Big Mac’s intentions could be serious. This transition illustrates how the revelation of the house’s existence prompts them to reconsider the validity of Big Mac's words, moving from amusement to apprehension about the implications of the letter and what it reveals about him and his secrets.
Overall, people's thoughts change from laughter and disbelief to curiosity and concern as they confront the reality that there may be more to Big Mac's message than they initially thought.