I work on my objectivity, but I know I will never succeed at achieving it fully. Humans are so colored by personal experience that it invariably infiltrates all facets of our lives. Therefore, we look for evidence regarding our preconceived ideas as proof that we are correct in thinking the way we do.
Examining all angles is not an easy thing because for many belief systems are tethered to the way we have lived for decades. If we find that we have erred, it could lead to regret we care not be exposed to. Hence when confronted with uncomfortable facts that are indisputable, some will admirably adjust while many will simply refute them as conspiracy to upend their sacred way of life.
It has never been easier to pick and choose personal truth in our history and in its extreme forms we end up with people doubting that the earth is a sphere or that the US ever put a man on the moon. While these people are among the fringe, there are plenty of others who walk a tightrope between respectable thinking and the outlandish. Finding a friendly ear for your own theory is not going to be a problem in this era.
The political landscape will irrevocably be changed because of this phenomenon and while I am hardly in favor of the kind of manipulation that the ruling class and the church were able to achieve in numerous nations (and here I think of Medieval Europe), I believe that this fragmented cafeteria-type choosing of truths is not going to do the world a great service in the future.