Reality will bite you in the ass...
We are all experts in denial. Who knows, maybe in order for us to lead a happy existence we need a dose of denial in our lives, but that strategy has it's limits.
You can float on a cloud of lies for awhile. You can convince yourself you defy gravity. You can tune out voices of reason or choose to ignore Science, spin & bluff your way out of tight squeezes.
Still, there are simple truths, harsh realities, things we can't really wish away. Ultimately too much denial will lead you over the cliff, it's a long way down, and there is sure to be a whole lot of pain when you reach the bottom.