The human condition is to underestimate the consequences of our actions.
In this observation we find the polar opposites of humanity: our ability to alchemize our surroundings for good, and our tendency to erupt despair from our decisions.
For example, an Olympic skier knows the inherent risks, but pushes off anyways in their quest for Gold. In this case, imperfect information yields a preference to do.
All the while, a business executive may know the products he markets are a leading cause of childhood obesity, but chooses to retain his six-figure salary regardless. In this case, ignorance is bliss.
Meanwhile, a politician may know a new policy will hurt a large cohort of people, but announces it anyways to affirm re-election. In this case, information isn't the challenge, it's the motive.
The know-do relationship is complicated. They say knowledge is power, yet we overlook what we know everyday in grand contrarian style - if we didn't, we wouldn't be human.
The only antidote to this tendency is to be self aware. It's to realize that space exists between what we know and what we do - and it's ok to lean on one over the other.
Perhaps this is the purest driver of contentment: when we reach symmetry between what we know and what we do. Only then will the outcome of our decision be truly predictable.