I am turning otherwise good play into disasters in league play. This has happened several times to me in my local league. Tournaments usually last 2.5 hours, starting at 7 in the evening. There is no money involved, just prizes and rankings.
At these tournaments I play tight and usually do well until the final table.
My problem is that i basically make one very stupid decision after an otherwise respectable night of play and blow opportunities.

Example: Typical night 2 nights ago. I had dinner at the bar where we play and a couple of drinks. 24 players to start. My cards had sucked all night, but by the final table I had played a few hands and tripled up. OK so far, not short stacked, not chip leader either. 7 players left.

Here's the hand that did me in. I'm on the button with KJ suited, my strongest hand all night. everyone limps, I raise 3x bb. SB and BB call, remaining players fold. All three of us had similarly sized stacks and of the three I have the smallest chip count, though not by much.

Flop comes 8-8-6, but my cards are the wrong color, no chance for a flush.
First position makes modest bet and says he wants to go home (worst bluff ever), 2nd position calls.

Now here's where I self destruct. I ignore all the signals: the 8-8 on the board, 1st position's feeble attempt to look weak and the early postflop bet. I go all in, both 1st and 2nd position call.

Position 1 has an 8 but winds up losing to position 2's boat.

Why did I make such a bad decision? The cuplrits that come to mind are mental fatigue and boredom. 4 bourbons and the meal didn't help either.

As i said this decision making behavior of mine has occurred several times with similar results. I only started playing live games in November.

Your thoughts?