I don't agree that it's all about pretending. Thoughts generally precede actions but it can go both ways too. For me, the benefit of aspiring towards objectivity helps affirm the mentality that I don't/shouldn't have a stake in the outcome, which keeps my mind open to more searching when I find that my presumptions don't (or do) match reality. In situations where I don't care about objectivity, I'm quicker to fall into confirmation bias.