> even if he's proud of being such, as you seem to be

Of course on Internet nobody knows you are a dog. But hey, I may be someone who wrote a part of the Linux kernel in 1994, ran IT operations for a company that was big (big!) and then almost vanished (not my fault :)) and produces open source that you may have even used if you are "technical" as you say.

And set up WG in so many places, including a frontend that unfortunately did not get the worldwide success it should have :)

With this modest introduction - tailscale works where wireguard does not. I am not sure why my example was not obvious. You can reach the machine at my friend's with tailscale, not with plain wireguard. Of course if you open ports in the right places then yes! And check a few more things.

Now - how would you set up plain Wireguard in a place without the possibility of exposing a port, or even that does not have a public IP - and initiate the connection from outside that place? I would love to learn something. Without rebuilding tailscale (or whatever other solutions with STUN or whatnot).