Sadly with chain stores that are owned and operated by a country wide corporation like Petco that kind of attitude will only get you shown to door rather quick. They all have the same standards and policies, don't follow them by the book they will just replace you. I worked at Petco and did get fired just for not doing what they said to do. I also worked at Petsmart and ended up quitting because they are just as bad as Petco. I'm sorry but if I was a 3D animator I sure as heck would not be looking to get a job to Petco who only pays up to $7.50 an hr. Even if it were to "take care of the animals"... sadly I was like you are when I was younger, sadly I also learned that you can't save them all... no matter how hard and long you do it.
I know when I was your age, I too thought "I knew it all". Man was I wrong and had a nice slap in the face one day as a really rude awakening call.