*sigh*
I guess my big mistake was using Bicycle on turn 20. My plan was to use Lighting twice on my next turn, tuck three cards each time, and claim the Monument achievement for the win.
Of course, there's no way I could've known Composites would come out, and my whole hand would be snatched. But still, my move was a big mistake. Big hand = big risk. Given that I was way ahead at that point, I had no reason to take a big risk like that. I should've left my score pile alone and just played on.