Absolute Poker 0.50/1 Hold'em (6 handed)

Preflop: Hero is Button with , .
UTG calls, MP calls, CO calls, Hero calls, SB completes, BB checks.

Flop: (6 SB) , , (6 players)
SB checks, BB bets, UTG calls, MP folds, CO calls, Hero raises, SB calls, BB calls, UTG folds, CO folds.

Turn: (7 BB) (3 players)
SB checks, BB bets, Hero calls, SB folds.

River: (9 BB) (2 players)
BB bets, Hero calls.

Final Pot: 11 BB

Results below
BB has 2s 5s (three of a kind, twos).
Hero has Ks 9h (two pair, kings and twos).
Outcome: BB wins 11 BB.

What the hell are these players thinking? He donks a blank turn against someone who raised him on an uncoordinated flop... with bottom-pair and horrible kicker. Can he really think his hand is good? I had no idea why he was donking that turn.

Someone explain to me the thought process behind these players, I'd love to know.

Thought process behind this fish:

"I have a pair. BET! He raised? I'll call to see what he has. I like how this mouse feels in my hand."

Turn comes:

"I still have a pair. BET! He called? I knew he was full of crap. Suited cards are sweet."

River comes:

"I have a set! BET! I win! Damn, I am a good poker player. I own these guys."

Notice things like what you could have, what the board shows that should scare his hands or any other poker related thoughts don't really cross his mind.

Although, I think those extra thoughts are probably giving the average donk credit.