Experience Tumblr like never before
i think one of my favorite details that i've noticed in rewatching 2012 again is that
Donnie and Leo, in writing, are very similar people who suffer very similar problems, but just different enough that they can't get their heads together on any given problem
Fungus Humungous, Metalhead Rewired, Mutagen man Unleashed, and The Fourfold Trap are good examples of them sharing a lot of behaviorisms and like. how they conflict because of that
They're both obsessive to the point of dysfunction, expect too highly of themselves, untrusting of anything that they perceive as a personal threat to their person (like with Leo and Metalhead, and Donnie and Casey), and worry a lot about doing the right thing
Especially Fungus Humungous, where we see their greatest fears are very similar in conception. At their core, they fear hurting people they care about and that they're horrible people for doing so and being abandoned by said people.
Donnie's fear is shrouded in self esteem issues and conveyed through his relationship with April, and Leo's fear is conveyed through his responsibility as the leader and eldest brother.
Not to mention they were both tasked with being a mentor to someone and had to carry the weight of being responsible for them, and. . . whatever was happening between Donnie and Don Vizioso and Leo and Shredder.