It's not a laughable question at all. Setting up a session for connecting locally on your LAN is very different (unfortunately) than setting up a session for connecting from anywhere on the internet (WAN).
This might become a lot simpler once IPv6 is commonplace. But right now, it's a non trivial process, unless you're familiar with how networks work.
There are guides here that should help. A planned in-app-purchase will simplify this immensely, but it won't be out until probably March.
viewtopic.php?f=6&t=5You need to look at the WAN guide.