Try to remember that they are all individuals ... I think that is the single biggest mistake snake keepers make ... trying to lump them all into one "mold" ... it just doesn't work like that.
Ball pythons usually go through a freak out phase from about 750 - 1250 grams ... I call this "teenage angst" ... heard that phrase used to describe bps fitting that description somewhere before (can't for the life of me remember where) and it fits. They start acting wierd ... maybe get overly hissy ... maybe flake out on food ... maybe become shy ... just different than they used to ... hormone related probably.
After they break out of that phase they tend to settle down, eat well, and become very mellow ... my big girls get a "queen of their domain" syndrome and rule the roost for sure ... mellow, but confident ... like there is nothing you can do to phase them.
That said, I have over 500 ball pythons and can show you at least 10 exceptions to every rule.
Hope this helps.
-adam