two TA tales

situation 1 : one of the better first year students comes up to TA1’s office. student : Um, can I ask you a question?
TA1 : Sure!
student : Well, um, about next year… will it be more of this? … I mean, with proofs and stuff like that?
TA1 : Heh? Well… eh… yes, I think so…
student : Oh, in that case, I think I’m going to study something else… situation 2 : TA2 is showing to second year (an exceptionally good year) that $SL2(\mathbb{Z}2) \simeq S_3$. He defined the groupmorphism, showed injectivity and surjectivity… So, we are done! Are we? student1 : Surely that’s not enough!
TA2 : Heh?
student1 : Not every mono and epi has to be an isomorphism.
TA2 : ???
student2 (to student1) : But clearly it is in this case, stupid. Finite groups is a small category! I’m not sure what story depresses me more…