You can no longer make medical or financial decisions for your children without proper paperwork.
Many people do not create an estate plan or do not consider all of the ramifications of their actions. This may be because they never get around to doing it, or they don’t believe their estate is big enough to require a plan.
Humans are great at avoidance. We don’t want to experience pain, be faced with unpleasant facts or deal with anything we consider to be too far in the future.