It's called 'role-playing' for a reason

The long-expected confrontation finally happened last night during our weekly geek session.  It also happend with the player I expected it to.  The players got their hands on a bunch of gun-powder, and Ed decided he wanted to try to use it to make a sort of nail-bomb.

I told him he'd have to try it with huge penalties since he wasn't proficient in either engineering or natural philosophy (the term 'scientist' wasn't coined until the nineteenth century).  He was basically a guy setting fire to a can stuffed full of gunpowder.  After three failures and nearly blowing his hand off, he started getting upset.  He didn't understand why he couldn't just see what he did wrong and do it differently the next time.  It was just like when he found out his character couldn't read if he didn't take a reading/writing skill.  Things like reading and scientific process weren't as all-pervasive back then as they are now.  There wasn't enough of it around that you could just pick it up as you went along in life, you had to specifically go out and find someone to teach it to you.

I also tried to explain that things like catapult-thrown fire-bombs had already been invented.  It wouldn't be that far a leap for someone who was actually skilled in dealing with gunpowder and firearms if Ed suggested the idea to him.  But by then Ed was in deliberate ignorance mode, where he gets bored or irritated and entertains himself by pretending to forget how the game works.