To add to the examples: let's say you hate how your roommate leaves dishes everywhere. But you decide to plonk your plate on a chair instead of loading it into the dishwasher. You feel like a hypocrite because you've criticized your roommate doing that -- does it mean that you should also criticize yourself? This is only your first time doing it, it's a stressful week, etc. But now you're wondering why you're allowed to excuse it for yourself and not allow your roommate to excuse when they do it.

All that discomfort you're feeling as you're trying to resolve two conflicting viewpoints (it's bad for your roommate to leave dishes around, but it's fine when you do it) is cognitive dissonance. You'll see a lot of people on Reddit misuse it to refer to you simply having conflicting opinions, but that doesn't quite capture it. Cognitive dissonance should encourage you to resolve your conflicting viewpoints, either by adjusting a viewpoint (it is also bad when you leave dishes around), or abandoning it (it's not bad to leave dishes around, period).