Krishna says, "All beings are subject to delusive ignorance (sammohanam) by the delusion of the pairs of opposites (dwandwa-mohana) springing from longing and aversion (iccha-dwesha) " (7.27). There are two fundamental delusions we are subject to. One is caused by three gunas (yoga-maya) and the other by polarities of longing and aversion. When one is transcended, another is automatically crossed.
Ignorance is the first level of delusion and misery is the consequence. This misery is nothing but the pain one gets -maybe with a time lapse, while chasing its polar opposite of pleasure. The next level of delusion is suppression where one gets trained to put up a brave or borrowed face to show the outside world that one is free of polarities of longing and aversion. They even look down on others and Krishna earlier termed them as hypocrites (3.6). But the reality is that these suppressions are hidden inside and come out at a weak moment.
To attain the final state of witness like a jnani , Krishna gives the path to overcome these delusions and says, "But those men of virtuous deeds, their sins obliterated, they, freed from the delusion of pairs of opposites, worship Me steadfastly" (7.28). It's being nimitta matra (an instrument in the hands of all mighty) by surrendering to paramatma .
A point to be noted is that in a given circumstance, a jnani and a deluded might behave in a similar manner of ignorance or suppression but the difference is internal. _Jnani_ attains an internal balance between pleasure-pain; profit-loss; victory-defeat and doesn't have any karma-bandhan (bondage of action). Deluded is imbalanced and his karma-bandhan is like writing on stone having a long lasting impact. This makes our understanding tough as examples rarely help.