I used to think I wouldn’t rationalize a losing position while I was invested, but after a hedge fund I was in divested from a large position, I was able to see the other way so clearly
This is quite funny. If it weren't for tax (and maybe liquidity in certain situations), this suggests a quarterly "sell everything" day might make sense. You'd sell everything on a friday perhaps, and come monday buy again after having the weekend to freshen your eyes.
alternatively you could take unbalanced bearish positions, like too many at the money put options, everyone can start thinking about the ways that becomes profitable by noticing the bear thesis and rooting for that for a little while.
then people could see which thesis is stronger and more probable, the bullish or the bearish ones.