Re: I forgot how to play poker.
 

I cash out half my remaining bank after a downspell, when it's due to questionable plays rather than bad beats. This usually happens when I go on an ego trip : "Wow, I can beat 20000/40000 NL !".

My remaining apparent br then dictates the stakes I play : whatever limit where I will have more than 500 BB.

Losing is also a good motivation to do some research.

Two books that have helped my poker playing :
"Winning, The psychology of competition", Stuart Walker
"The Psychology of Trading: Tools and Techniques for Minding the Markets", Brett Steenbarger