What's Normal?

The girls who were here and I went with my brother and sister this morning to pick blackberries at a nearby blackberry orchard. I don’t know what the real name should be, so I’ll use the word “orchard”. We got up early, were out of the house by 6:25, and on our way to the restaurant for breakfast and to meet Sis, then on to the berry farm.
The girls did generally well at picking, but mostly had fun with each other and with the “berry bugs” and the “berry snakes”. One of the girls saw a garden snake and called it a berry snake, and there was some kind of insect, like a locust, that one of the others nicknamed a berry bug. Of course, the bugs and snakes were going to eat them, etc and there were appropriate shrieks and laughter about the critters.
My brother said during the picking time that if one didn’t know differently, one would think that these girls were “normal”. I replied that most of the time they were indeed normal, but there were times where triggers of some sort, usually unknown even to the girls, cause them to not think clearly and do something they otherwise would not have done. Or they have not been taught proper interaction techniques or responses to certain environmental stressors. Or there is something else going on of some kind.
We all have times when we’re not normal, I suppose. It’s just that most of us react appropriately to those times and redirect ourselves back to normal or accepted behavior. These girls, for some reason, can’t do that appropriately.
By the way, what’s normal?