We noticed that Rowan has a little spot that is discolored on one of his front teeth . So , when we took him for his 12-month appointment with the pediatrician , I asked about it . And , her response was , " I ' m sure it 's nothing , but it could be a cavity , so I 'll refer you to a pediatric dentist and you should go see her soon . " All I heard was , " He has a cavity " Of course , I freaked out a bit .

Give answer the following question using evidence from the above passage: Why might I have freaked out when I heard the word cavity ?
I have been meticulous about brushing and caring for his entire mouth