You know how when you have cavities and you have to take multiple trips to the dentist because they won't numb both sides of you mouth at the same time? Yeah, well they will numb both sides of your mouth at the same time when they accidentally numb the wrong side of your mouth first and then they have to numb the other side of your mouth to get the job done.
Things that are impossible to do when both sides of your lower jaw are totally and completely numb:
1. smile
2. drink soda from a can
3. chew food without chewing your lip
4. whistle
Also, before I went to the dentist I went to a lab to get blood tests (going to find out what is up (or down) with my thyroid/adrenals) and during the third vile of blood extraction I started up a conversation with the technician. After she was done taking my blood, writing on all of the labels, sorting the 46 viles, putting them in the blood shaking machine and them storing them away she continued to chat away with me leaning back on the counter. It wasn't too bad since she had a pretty interesting life, but finally (40 minutes later, I kid you not) I had to admit to her that I was trapped in the seat and couldn't get out and she said "I know. I don't want you to leave." which made me break out in a cold sweat until she laughed and opened the swinging arm of the chair so that I could make to the dentist on time and get both sides of my jaw numbed.