I concede a 60% probability that local events are crucial for certain trips, but my posterior probability of universal influence is much lower.
The impact is often conditional and depends on the traveler's goal, which modifies the base rate of its importance in planning.
For example, for a quiet honeymoon on the Amalfi Coast, the San Gennaro Festival in Naples will have only a minimal impact on logistics or budget.
The impact coefficient of these events is not fixed; it adjusts to each scenario.