The "insidious" of illusions is that they often remain unrecognized, otherwise they would logically not be;). They arise because our sense of reality is different from the truth. Our ego diligently defines itself to make decisions. People who reflect know about the dilemma of subjectivity. On the one hand we want and should decide, on the other hand it should be correct. In addition, a clear yes or no has a different effect than a "weak one". So it matters how much "energy" we put into our thinking and acting. Also, we often can not remotely guess the scope of decisions. What yesterday was good, is good for today and should be good for tomorrow. We rely on memory and experience to more or less pursue our goals. If it doesn't work, we may blame others or even the whole universe. Buddha once said that we are what we think. So it would not be wrong to hunt that phrase through the brainwings a couple of times, wondering if we really are God. We are part of the big thing and are able to integrate. Waves strike us, but we can also get some going.
Misogi is a cleansing ritual that lets us understand with ice-cold water, which wretchedly weak creatures we are. Propably the most people will experience this the first time. "Cold, cold, cold, that's totally stupid, I'm freezing, in the end I'll get sick." In principle, Misogi is like the effect of cold showering, only longer and deeper. By self-overcoming our sensors are recalibrated and the ego is put in its place. This holistic series of experiences of cold water shows us how subjectively we judge something and that we are able to change. Also, that we are capable of more than we think, that body and mind are in a close connection, that relaxation relaxes, that willpower can change a lot through reflection and finally we reach centeredness and find our center.