Here's a story about the importance of details.
My party was exploring a long abandoned subterranean complex. The tunnels in this complex were 10' wide by 10' tall. Our party had been sent into this location by a noble who was tired of losing peasants and livestock to the monsters who had taken up residence.
After several days of slogging through this complex (with various encounters and rewards) we were ambushed by a troll in one of the passages. Our DM described the troll rushing us with a pole arm raised overhead and striking down at the lead party member.
Remembering the earlier description, I asked how tall was the troll? About 7' tall. How big was the polearm? About 8' in length.
I reminded the DM about the passageway size and he decided that the troll (not being too bright) did try to swing the pole arm overhead and got it stuck in the ceiling. This allowed our party time to attack/defend and defeat the troll with no losses.
At the conclusion of the battle, the DM awarded me extra XP for my attention to detail.