Jekyll and Hyde draw opponent

One of my opponents tonight was a complete maniac. One hand he was on the button and raised, I 3 bet with QQ24K, he capped and I called. I drew three and he drew two, he bet post-draw and I called. He showed a pair of sixes and I won the pot. The next four out of five hands he power folds, three of them pre-draw. How does a player go from too LAP then to weak-tight or fold-tight even in a matter of one hand ?