So, I had a recent game with both Pirate and Charlatan. This is an interesting combo since Charlatan, by making Curses into Treasures, can trigger Pirate's reaction, both for your opponent's play and for your own play. Anyway, at one point, the hand I drew had a Charlatan, a Pirate, and $5 worth of Treasure. So, my plan was, when it came to my turn, to play Charlatan and react to my opponent's gain with my Pirate. That would give me $8 for that turn and an extra Gold on the turn after that. But then my opponent played their own Charlatan and I accidentally used the reaction. So, I ended up with a total of $11 to spend on turn, with no extra buy, and not a Colony game, meaning that the extra Gold went to waste. And no extra Gold on my next turn, which turned out to be crucial as I was just a little short of being able to buy a Province on that turn (I think I ended up with $7 if I'm remembering right, but definitely an amount that an extra Gold would've been crucial). So, I ended up only being able to buy a Duchy instead of a Province. There were enough turns after that that I can't say for sure that it cost me the game (since both of us would probably have made different choices), but the final score ended up close enough that it likely did. Very annoying mistake