I'm not saying it is like this, it is just a thought I would like to share.
Some abilities seem to get passed on through generations, and especially in the Petrelli family where the father and the sons have some kind of power that collects other abilities. Angela said that Nathan was born without power... But what if he also had a power which was extremely dangerous, and therefore Arthur took it. Instead they gave him a new power.
Maybe it would be totally unnecessary for the series to include such story, I don't know. What do you think?
I will probably get a comment that says that this already has been discussed, like everything else new guys come up with... I couldn't find anything anyway.

