33. Dumbledore is stuck in a time loop.
He works his way through a version of the main timeline, allows Snape to kill him on that night, and wakes up October 31st, 1981 as the alarms alert him to the death of the potters; he repeats his timeline refining the chain of events to allow him more time and does only to wake up on Oct 31st again.
They say the definition of insanity is doing the same things and expecting different results. It takes some time for him to realize that no matter what fine adjustments he makes to the plan the end is the same.
He ends up back on October 31st with the monitor at the Potter's alerting him to the disaster. Only after exhausting his library of knowledge does he finally reach out, having relived the last few hours of October of 1981 for the hundredth time.
He's tweaked every variable of Harry's school years to a well-oiled machine, even upset the chain of events a few times, and allowed Harry to die in a couple of rounds; ironically, he lived the longest in one of the timelines where Harry died early, if being imprisoned next to his old friend Gellert in Nuremgard can be considered living.