Lol I didn't say I was going to trade in what I knew in the process
How much do you know about surgery? If you needed it, could you direct somebody to do it for you without anaesthetic? Do you know how to grow and purify penicillin? Are you willing to eat partly rotting meat, bread with sand in it and vegetables contaminated by human faeces, all of which haven't undergone any sterilisation or preservation process but salting, pickling or cooking? Do you prefer to risk your life on unsterilised water, or spend a large portion of your life cutting firewood (assuming you're in a land where that is allowed)?
Medieval style worlds would suck to live in.
Also, Pratchett is a god. He's the Douglas Adams of fantasy, with a much longer list of works.