My partner opened 2NT (20-21) and I raised to 3NT. I don't know how he found it, but North led the ♠T, which went Q,K,A. We were destined for a bad score when partner took the heart finesse into South and we were limited to nine tricks, despite holding a combined 31 HCP. A lousy 18.3%. This is one reason I lose at bridge, my opponents have a habit of finding non-standard actions that work beautifully for them.
"Brilliant lead"
"I had to lead a major"
"Of course you did"