Say my character was a thief that was caught crossing the border. He's an expert at using stealth and bows. But while in Skyrim, he wanted to repent his ways. He joins the companions and decides to get trained in the art of using heavy armor and a sword
Morrowind and Oblivion meant I had to use light armor, a bow and my sneak skills for the rest of the game, because I declared myself a thief at the start of the game. Skyrim means my characters skills and specialities can change organically depending on the outcome of the game, as in real life.