Disclaimer- I don't own Harry Potter or Peter would be a cockroach.
Peter Pettigrew did not understand harry Potter, even after three years.
They had almost lived together and he still hadn't figured the boy out.
Harry had let him live.
Harry had been given the choice, kill him as revenge for his parents, but he didn't do it.
That should have been impossible for the passionate boy who challenged death for a friends sister, or who went through all the traps to get to the stone, before someone else could. It should have been impossible for him to forgive Peter.
But he did, it seemed.
Furthermore, the same boy who seemed to know nothing of his past, knew his parents more then those who knew them.
The boy would attack a teacher, but protected Peter. In what world does that make any sense?
The boy just made no sense.
He was completely unpredictable.
Peter must warn his master.