but you cannot hide the building
Seriously though, if you've got the normal domestic NAT/router in stealth mode, such that it doesn't reply to pings and silently ignores incoming connections, contrary to the behaviour specified in the RFCs, then it's really rather difficult for anything to get at you[1] that you don't invite in[2].
The building is pretty well hidden - anything that anyone outside sends to your IP address will produce absolutely nothing at all whatsoever in response - sounds like a successful attempt to "hide the building" to me.
[1] It's not impossible that there would be bugs in routers that would be targetted by malware, but it's not an everyday reality you have to worry about.
[2] Like, for example, choosing to download and install and run a virus, eg by deliberately opening an attachment in a spam email.