Okay, but unless you've poked a hole through NAT (and if you have, presumably you know what you're doing), what are those incoming connections going to connect to?
If there's nothing to connect to, is there really an incoming connection?
They connect to whatever IP is specified in the packet's "destination IP" header field. It's exactly the same behavior as if there was no NAT going on.
If there's nothing to connect to, is there really an incoming connection?