I did something similar to Luu a few years ago.
I was playing $1/$2 no limit. I had lost some money and I was down to my last $200, trying to work it back uver $1000.
The UTG player, who had been at the table for about an hour, and who had done nothing out of the ordinary, raised to $50. The action folded to me in MP and I looked at KK. The only hand that I could put UTG on was AA. I thought for about three minutes.
And I finally called.