Rachel is pretty much everything I wanted to be as a teenager. Confident, smart and not willing to take any bullshit. And this is just the beginning! She only gets better (and certainly more ruthless) from here. She is the ultimate warrior of the group.

Jake uses the term "I guess" a lot in his internal monologue. I don't know if that is a stylistic choice because he is a teenager or if it's the author's intention to show his insecurity as the de facto leader of the Animorphs. I'll have to keep an eye out in the future Jake books to see if this changes as he matures and becomes more confident in his decisions.