weird creatures

Sometimes people act like some weird creatures. I met someone who's behaviour changes like that: Whenever she's ok- not necessarly happy, but in a good mood- she is very opened. Available to talk and change thoughts with others... Unfortunetly, she recently became smbd else. Moody, histerical, with a large false smile and very critical abt the others. I noticed that she can ignore her own "wild attitudes" but if smbd else does the same thing she'll be screaming around as if it would be matters of life and death..
I wondered at first if we all do that.. and i noticed the answer was "noup!".... I even thought that o overreact because i'm used to act freely and not to be told how to do my things around. But regarding this particular person one said " Haven't you seen that i'm running like hell away from her?! I really dislike the way she shouted at me!" And i somehow got relaxed because i wasn't the only one....
So i noticed that whenever i'm stressed out i let everyone know. I am not perfect and i use "the Voice" even if i don't want that. At least i can let people know and let them the choice to be beside or away from me- i'm not very funny when i'm agitated. And i noticed that others do the same... This exception i'm telling you about is the kind of person who feels good among rules and "settings"... Isn't a curious fact that even at my job i have freedom? I love freedom... Funny thing that don't adapt very easy with new things... And how come that people foud of rules become wild inside them?