No matter how much we plan for, there is always (ALWAYS) the possibility the unexpected could happen. Most people spend most of their time comparing Door A to Door B without ever realizing that there is a third Door they are ignoring entirely.
Door C has a tendency to open itself at the least expected moment. If you don’t anticipate the possibility of the unexpected, it will always surprise you (often negatively).
Always plan for the other events that could happen because they will.