For sanity reasons:
That shit will happen - but you know this. Shrug it off, that's what I do ... just keep remembering: these are the plays you want, especially pre-flop. If it wasn't for bonehead plays like this, then you wouldn't be up so much this weekend.
Strategically:
He called your PFR of $10... the flop was all low cards with a poss straight (and maybe even a flush draw out there??). When he pushed all in, what made you think you had him beat? Did you already have him pegged as a fish? KK is great, but compared to the size of the pot in relation to the size of the bet... you might have considered folding.
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