No... Every game eventually will die. Nothing you do can prevent that from happening. But for now, you could make an RPG that is full of ideas from the back of your mind.
what interest you? I'm really into war, battle, etc, and love studing WWII. I want a pilots liense, so the combinaton of the two ishow i came up with the 'Flyboys' series. Just do something that interest you, and has an easy storyline thats not too predictable. By easy, i mean easy to come up with, follow, continue, and eventually, end
There are many Medieval etc RPGs out there already. I like the alien one
If you're adamant with the Villager->Knight thing, 1) Set up a village/small town 2) Set up a sort of map 3) Set up properties which your char. can own 4) Set up NPCs with missions/stores etc.