We all use it sometimes. For instance, since we see our child every day it is just as hard to see that he is gradually losing muscle function as it is to notice that he is growing taller. We love to measure what he's gained, but we hate to find out what he's lost, and so we don't until we have to.
But it may be that you are so busy denying the diagnosis and its implications that you are unwilling to do what needs to be done, things like stretching exercises, or looking around for an accessible house. In that case, your child would suffer from your unwillingness to face reality. And that would not be good.
Don't think it couldn't happen to a realist like yourself. The desperate need to hang on to a cherished belief may make even the most hard-nosed adult want to play make-belief for a long time. It really happens.
And so it is good to ask yourself every now and then how much you play peekaboo with the facts, and put off doing things because they bring up unpleasant thoughts.
