A toothache is one of those things that grows on you. At first, it's a little hint to go to the dentist. But you can get used to chronic pain, and almost forget it's there.
Meanwhile, living with chronic pain is one of the stressors that can set off depression, which can lead to fatalism and not wanting to make the call to go to the dentist, so you just take an asprin,
or drink that extra beer. soon, it's 6 aspirin a day and you've made the appointment, but then you get captured by neonazis.