In Mrs. Frisby and the Rats of NIMH, the animals have no choice but to figure out who and what they are: the rats need to figure out how to live with their new super abilities and Mrs. Frisby and her kids learn some surprising secrets about their family. Which is all well and good except for the fact that figuring out who you are and where you belong in the world is hard work. The rats alternate between liking who they've become and feeling tormented by it. Mrs. Frisby, similarly, has to come face-to-face with the fact that her husband kept a big secret as well as the fact that she is much more than just the sad, old widow she thought she was.
Figuring out who you are is a real pain. The rats spend too much time worrying about this, when really they should just be focusing on survival.
Even though it is painful for them, figuring out where they belong and what type of life they want allows the rats to live up to their full potential.