The point is that outside traffic isn't even reaching anything you even have control over, because you don't have a public IP (i.e. the ISP won't set up port forwarding for you). Let's say you wanted to directly send a packet to my phone. There's no way we could make that happen even with both of our cooperation because my phone doesn't get a publicly addressable IP.

Nat:ed ip's are a PITA. But any decent ISP will give you a public IP if you ask. We are running out of ipv4 addresses.

> if you ask

And pay ;)

Getting a static IP on an internet plan here in Australia will typically cost around $5 a month, and not all ISPs offer it on residential plans.

I hope that goes away with ipv6