For a rational person with infinite processing power, my point doesn't apply. You can also neglect air resistance when determining the trajectory of a perfectly spherical cow in a vacuum.

For a person of limited intelligence (i.e. all of us), it's typically necessary to pick easily-evaluated heuristics that can be used in place of detailed analysis of every decision. I last used my "people offering me free stuff out of nowhere are probably trying to scam me somehow" heuristic while opening mail a few days ago. If ciphergoth's interlocuter had been subconsciously thinking the same way, then this time they missed a valuable opportunity for introspection, but it's not immediately obvious that such false positive mistakes are worse than the increased possibility of false negatives that would be created if they instead tried to successfully outthink every "cannot lose" bet that comes their way.