Yogi: When there is good memory or good feeling, because it is not causing dukkha, the mind doesn’t want to let go of the experience and also forgets to be aware.
Sayadaw: That is because of lobha. Suffering, there is anger; if it is pleasant, lobha will come. It is because lobha is present, awareness and wisdom cannot be there.
People don’t like suffering/unpleasant objects; they like pleasant objects; but when there are pleasant objects, the mind forgets to be aware because it gets involved.
That’s why yogis get stuck with pleasant objects.