boardreading mistakes

Tonight I misread the board twice in a 5 hand span. I'm not tired, drunk, or tilting, so I'm not sure what's going on. Perhaps I just need a break.

In the first hand, someone limped and I reraised with QQ. Someone called behind me, and so did the limper. The board came Q 6 4, with two spades - I had top set. Usually I'll bet to protect against the flush, but I checked here, deciding consciously to vary my play and not be afraid of every draw.

The turn came the 6 of clubs, putting 2 clubs on the board along with 2 spades. The player before me put out a half pot bet, and I decided I needed to raise to protect against both flush draws. I raised big and they both folded - a nice pot won by me.

Except, you doofus, that the 6 paired the board, giving you a nice floating boat. Why are you protecting against flush draws again?

In a later hand, I have 99 and raise a limper. He calls. The flop comes a very satanic 6-6-6. The villain minbets - this usually means he has nothing, so I raise. He calls. The turn is a King. I bet - he calls again.
The river is the fourth 6. My first thought is "well, I'm really glad he doesn't have quads". He checks and I bet big, for "value". He folds. As he's folding, I realize that he had me beat if he had any card higher than a 9 in his hand - the fourth 6 counterfeitted my boat and turned my nines into kickers. Lovely.

Both hands won, both played poorly.

I actually finished third in this tourney, but didn't take much satisfaction in the victory. You'd think after this amount of time I wouldn't be making mistakes like these. I did play fairly well at the end - a hyper aggressive player was the big stack and to my left, making it very difficult to get into the pot. I was able to trap him into putting a nice amount of money into the pot with AA, but he was raising really often and I needed to take a stand - which I did, with KQs. It wasn't the best hand preflop, or afterwards.