My galah used to be very affectionate, now he's scared of everything?

did anything change recently in the house hold, people sometimes don't realize that it can affect your pets to, or is there a new person coming around that wasn't there before. there really alot of factors that can be blamed for his recent behavior, but in my experience almost sounds like maybe a person that did something (maybe not to the animal, but around it or where he could hear it). if there was a change, i would investigate that, otherwise unsure. hope this helps and good luck