The thing is except for a handful of people noone knows that you are the dragonborn or that you killed alduin. There's no facebook, twitter or CNN in Skyrim so it's to be expected that the common people don't know your face.
Y'know, if sombody mods in a "Jean-Luc Picard facepalm" animation, I bet lots of PC players would use it all the time
People know that you're a mage from college, but they don't know about your exploits there. How?
Heck, you can even Shout in Solitude and nobody will even bat an eye, save for covering their ears and send you to jail. I mean, hello? I'm SHOUTING here, ever thought that I'M the Dovahkiin?

