What does delusion feel like?

Delusion is our normal state so we are all familiar with what it feels like. Delusion is this niave realist, rational, or materialist complacency. The world is absolutely nothing like we think it is.

"What does delusion feel like?": total fine, true, like a refuge and right for common folk, and as the origin of all pain for those with eyes.

How does this answer feel?

What ever feeling, it's to be regarded as a cancer. That hurt's right?

1. When you truly uproot all delusion, you are a complete Buddha. Don't think you'll get rid of delusion in one day, there are many stages of a bodhisattva (someone who has achieved initial Enlightenment). Even the brightest states of mind can be delusion (not that they shouldn't be cultivated!) as the Ten Corruptions of Insight would indicate. This is because delusion is the root of all three poisons including delusion itself. The whole chain of suffering (2nd Noble Truth) began with craving, which has ignorance as its first cause. Working towards Enlightenment is like working with delusion because you are finding states of being that are purer and purer (jhanas) and further and further away from delusion--yet still delusion until like the SNAP of a finger you can drop all the skandhas and rest in your true being that is beyond emptiness and existence. But this only happens after finding emptiness and living existence purely as well. Master Nan gave an example saying it's like taking two sticks, rubbing them together to make fire, and thus burning them away... fire is gone, stick is gone.
2. Don't label it as delusion. It is what it is. Hatred is not hatred, love is not love, delusion is not delusion. It is empty. Recognize the empty nature of it. The more you try to push away something, the stronger it will get. (see Heart Sutra and Diamond Sutra Explained by Master Nan)
3. During meditation. I feel delusion oftentimes as a clamping down SOMEWHERE in my body. By consciously remembering to relax it, I also remember to let go of certain delusions that caused the clamping. This delusion poison can mix with the other two poisons and cause mixed sensations. Also remember not to think about this too much and subconsciously create such feelings in the first place. Get back to your concentration practice as soon as you can. When I clear these tightenings up correctly, I feel like I am floating and all my muscles feel completely at ease. Attachment to the state can cause delusion again but ignorance of the imperative to be-relaxed-and-nakedly-aware-without-judgment-or-outcome can also increase delusion.
4. Read the Surangama mantra, it has some interesting puzzles to overcome the roots of our ignorance and delusion... especially meant for our "Dharma-ending age"

Many gross emotions are included in the category of 'delusion', such as confusion, fear, jealousy, envy, possessiveness, selfishness, egoism, etc. We can know what these emotions of delusion feel like because they are gross/coarse.

As for the subtle delusion of 'ignorance', where 'becoming' ('bhava') or 'self-existence' is created, we can only 'feel' this when becoming ceases. In knowing the absolutely clarity of non-becoming, the mind can sense or feel the pollution of becoming. But this is very subtle.

Anyone who is not at least a sotapanna experiences delusion. A sotapanna is someone with Right View. They understand the Four Noble Truths, Dependent Origination and more. An unenlightened person has misconceptions about the Dhamma because if they didn't misconceive the Dhamma then by definition they would be enlightened.

Delusion is both cognitive and emotional. Emotional delusion is easier to recognize. It manifests as confusion, or doubt. But any ignorance of the core Dhamma is delusion. One way to remove this is by studying the suttas. By learning, analyzing, testing, and applying the teachings of the Buddha and his enlightened disciples you can clear up deluded thinking, wrong ideas, mistaken assumptions, and in general Wrong View.

It feels pretty painful, I cannot point to a sensation that would belie how it feels like, but it is pretty painful. There is a term used by the Buddha called "dukkha patipada", in one sense it used in reference to how people with "strong roots" experience progress that is more or less painful.

Cheers.

Thinking is delusion. Understanding is delusion. Ideas are delusion. It just is. No idea behind it. But, just by saying it is, we create an idea and block it out. Anytime words form, we forget what it is.

Delusion can manifest as mental vagueness, blankness, the appearance that time is going by and nothing's changing, boredom. It's like a gauzy veil drawn over the reality of constant change, allowing you to believe that "nothing's happening" (which is never true).

I think that 'aversion' and 'desire' are opposite/complementary extremes of each other.

Similarly I think that 'delusion' is (defined as) the opposite of 'truth' (sacca/satya, the four noble truths) and (I presume) other 'true dharmas' (for example, one delusion might be a wrong view about 'self').

So I guess that you can be 'aware of delusion' whenever (if ever) you're aware that you have forgotten 'right view' or 'right mindfulness'.

If it's the 'root' klesha, I suppose it has many manfestations, but one of those is presumably any addictive behaviour: repeating the same harmful mistake.

You're right though that at the least the "The Four Frames of Reference" section of the Anapanasati Sutta only talks about "putting aside greed & distress with reference to the world". Maybe the parts of it after that i.e. "Awakening", "Knowing", and "Release" are describing the opposite of "ignorance".

Also, in The Taste of Freedom Bhikkhu Bodhi writes,

Three kinds of feelings have been pointed out by the Buddha: pleasant feeling, painful feeling, and neutral feeling, i.e., feeling which is neither pleasant nor painful. These three classes exhaust the totality of feeling, and one feeling of one class must be present on any given occasion of experience. Again, three mental factors have been singled out by the Buddha as the subjective counterparts of the three classes of feeling and described by him as anusaya, latent tendencies which have been lying dormant in the subconscious mental continua of sentient beings since beginningless time, always ready to crop up into a state of manifestation when an appropriate stimulus is encountered, and to subside again into the state of dormancy when the impact of the stimulus has worn off.

These three mental factors are lust (raga), repugnance (patigha), and ignorance (avijja), psychological equivalents of the unwholesome roots of greed (lobha), hatred (dosa), and delusion (moha). When a worldling, with a mind untrained in the higher course of mental discipline taught by the Buddha, experiences a pleasant feeling, then the latent tendency to lust springs up in response — a desire to possess and enjoy the object serving as stimulus for the pleasant feeling. When a worldling experiences a painful feeling, then the latent tendency to repugnance comes into play, an aversion toward the cause of the pain. And when a worldling experiences a neutral feeling, then the latent tendency to ignorance — present but recessive on occasions of lust and aversion — rises to prominence, shrouding the worldling's consciousness in a cloak of dull apathy.

[...]

Under the dominance of lust he is drawn to the pleasant, under the dominance of hate he is repelled by the painful, under the dominance of delusion he is confused by the neutral. He is bent up by happiness, bent down by sorrow, elated by gain, honor, and praise, dejected by loss, dishonor, and blame. Even though he perceives that a particular course of action can lead only to his harm, he is powerless to avoid it; even though he knows that an alternative course of action is clearly to his advantage, he is unable to pursue it. Swept on by the current of unabandoned defilements, he is driven from existence to existence through the ocean of samsara, with its waves of birth and death, its whirlpools of misery and despair.

So the three poisons (lust, anger, ignorance) correspond to three types of feeling (pleasant, painful, and neutral); and delusion therefore is associated with a "neutral" feeling, and "consciousness shrouded in a cloak of dull apathy" and "confusion".