Lelia mentioned that comments which do not recognise the feelings of the hearer can be invalidating. There is a cartoon called Four-Box World (I thought, though I can't find it) which gives a simple, often pointed and ironic, outline of the possibilities. In this one, I have occupied all four boxes at various times: I have been dismissive of others both unfairly and fairly; I have been dismissed both fairly and unfairly. It should give me pause, but it doesn't.
Before discussing full anosognosia, it is worth noting how thorough lack of insight can be even in ourselves at times. We equate mood with competence, for example. Christians very easily equate mood with faith. It is not that we consciously make this connection, but that all those positive images just make more sense to us when we are feeling upbeat. Stepping out in faith, believing in forgiveness, expecting a miracle - all those cliches. And when depressed, these seem elusive, and we fear our worship is empty and our God disappointed in us. Those others, who seem able to live in the cliches at the moment, we resent terribly. We may get especially ticked off at the expressive worshipers or whole denominations at such points: Yeah, all this pumped up singing and dancing, you're just doing on Sunday mornings what kids do in clubs on Saturday night, don't put any spiritual shine on it.
Rather small of us, but we do it - because mood feels permanent. It lies, and tells us it provides insight. But either way, it doesn't. When you are depressed, use whatever tricks you can to fool your body back to baseline, even if it's false excitement. When you are cheery, caution yourself that this also is not theology, but chemistry. And in neither case should you guilt others with your cliches.