Question: Didn't that happen in the 80s cartoon? I don't think you can call yourself a "hardcore TMNT fan" without knowing about it.

Not that I am one, but really you should know better...

I think it makes so much more sense. I remember being a kid watching the first live action movie and being a super fan, and even then I thought, "A rat practicing ninjutsu in his cage? That's a bit hokey". While TMNT isn't real grounded in reality to begin with, I think this change makes Splinter's character a bit more believable.

i'm not sure. i dont mind because it was how it was in the cartoon and to me it makes more sense that he was a martial artist that turned into a rat rather than a rat that turned more human like.

to me that makes more sense as to how he would know more about the human world as it were. in this series it makes sense as there is 3 examples of people being turned into mutants and seems like it goes be the "you turn into what your touched last" thing

yeah but the point here is they act like teenagers. before there was never anything to suggest they were teenagers in previous series. in this they look and act like teenage boys

Maybe not the original cartoon, but yeah, everything else pretty much portrays them that way.