One moldy strawberry

As I sat in the waiting room of the dentist I was trying to understand how what started as a mild discomfort in one tooth now three days later has caused major pain and became unbearable in every tooth on my lower jaw and swelling in my neck and cheek. How can one bad tooth take over my quality of life? The same is true if you leave one bad past person or problem in your life they will cause havoc in all areas of your life. If you leave a moldy strawberry in a container of good ones if it is not removed immediately the mold will spread quickly ruining them all.