Undone diligence

On Friday night, with the exception of two hands, I played well. I made the same mistake on both of them - I didn't perform the due diligence I needed to perform. In both cases, I lost to a straight with a two pair. In both cases, the up cards were showing 3 cards to a straight. I'd like to say I figured my opponent was bluffing in each case, but the sad truth is that I didn't see the straight possibility either time. That's a recurring hole in my game which I need to plug.

buy_in entry_fee num_players num_hands place winnings

 45000      5000           6       115     3        0

delta: $-50,000
8-game tournament balance: $420,000
balance: $9,867,770