Frame that. Always focus on what you know to be true. Do not kid yourself. Do not rationalize.
I don't suppose that is a good clinical definition of mental health, but it is useful. That quote has been an anchor for me in my recent life. I went for a long time, ignoring reality because it was less painful (in the short term) than accepting what I "knew" to be true. In the end, it is an immature, cowardly, foolish approach to life that will only hurt you and everyone around you.
Another quote on reality found on the Overcoming Bias blog follows:
Owning up to it doesn't make it worse.
Not being open about it doesn't make it go away.
And because it's true, it is what is there to be interacted with.
Anything untrue isn't there to be lived.
People can stand what is true,
for they are already enduring it.
-- Eugene Gendlin
Rationalizing is a form of not facing reality. It consists of making up a reason or excuse to make the facts fit some preconception of what one thinks should be. An example from Wikipedia is, "...consider a person who bought one of the first home computers in 1980 primarily motivated by the excitement of playing with a computer. If he felt that his friends would not accept "having fun" as a sufficient reason for the purchase, he might have searched for other justifications and ended up telling them how much time it was going to save him in doing his taxes."
That for me is an example of rationalization that is fairly harmless, especially if he doesn't believe it himself. It's more a form of lying to protect oneself from ridicule. It's not good, but in my opinion begins to be damaging when one starts to actually believe or accept obvious rationalizations.
When you receive a rationalization, you may experience cognitive dissonance. You know that feeling. It's where what you believe is not quite the same as what is happening or what you are being told. It's that "feeling in my bones," the "I knew something wasn't right" thing. Listen to those clues. Follow up on them. Try to understand whether your mental model is faulty or the external inputs are.
Why We Ignore Reality
Adlerian psychology believes that most psycholgical problems are attempts to overcome feelings of inferiority and inadequacy. Now just to keep things straight and objective, remember that feelings are facts (i.e. reality). So if you feel somehow inferior or inadequate, it does not mean that you are inferior or inadequate, only that you feel that way. The reality is the feeling, not necessarily the underlying opinion.