Describe a game experience that changed how you play.
A few years ago I was CKing my first Castles & Crusades campaign. The first level party got attacked by 10 goblins late at night. One group of goblins confronted the party while another group waited in hiding. During the second or third round of combat the second group of goblins were now stealing the party's belongings. The hero's managed to kill all but two of the goblins. These goblins escaped with Larry the gnome's gold pouch, so of course the party chases after them into a dungeon.
While searching through the dungeon the group comes into a large room littered with bones and debris. There are 12 tall columns stretching to the ceiling 20 feet above. At the north end sits a stone throne on a raised dais. Dust has settled on everything in the room. Well, Larry's first action is to run through the room and sit upon the throne. Now the rest of the group is pissed off. Larry activated 5 skeletons with his antics. What does he do next? As he runs for the nearest door he gets hit by a skeleton taking him down to 1 Hit Point. He then closes the door behind himself and readies his next action. Larry asks if he can open the door shoot an arrow and then close the door all while a skeleton is trying to come through the door. I told him no you can't do that. This brings me to my point. I really didn't like telling the player he couldn't do something. After that night of gaming I made a resolution to myself that I would do the best I can to allow a player to do what he wants no matter what the consequence is. From that point on I try to never say no to a player's request. Obviously there are rules to the game and I just can't accommodate a player's request all the time but I can try.