"Spontaneous Schedule Combustion"

Making plans isn't something easy to do, so in turn; you become someone who's spontaneous. Someone who believe in making plans by the day, without scheduling ahead because you just might get let down. So what happens when you do, in fact, get let down by a "planned-ahead" plan? Let's say something occurs that causes this plan to be canceled, or postponed... or even rescheduled. What do you do now? Do you plan something else? Wait around for this plan to be capable of recurring and retrying? I wonder... do we keep schedules to avoid making plans?