An interesting question and an apt moment for Arthur Lee's particular brand of nihilism, "you think your happy and you are happy that's what your happy for".
Truth is seldom completely grasped even small matters as it is subjective to input, but the closest we can come to reliant truths are those based on science. Whatever our spiritual inclination, we will all die without knowing the answer to the many fundamental cosmic truths, if indeed they exist, such as those that deal with consciousness and existence. For most of us life is pretty much a 'Western Front' and our lives can work quite well if filmed from just the right angle that allows a mix of truth and happiness to keep us from the pills or the cells.
Personally I think that a state of happy ignorance is highly underrated and it certainly works for some - check out Laura Bush's smile and you will see what I mean.
Best regards - HS