A Momentary Attention Lapse is Not The Same as Forgetting:
Rav Bunim of Peshischa zy”a once entered the Chozeh’s room and saw that he seemed very worried. The Chozeh told him that he had just transgressed a prohibition of the Torah. It says (Devarim 8:11): “Watch yourself, lest you forget Hashem, your G-d.” He had just stopped thinking about Hashem for a moment, so he feared that he had committed this sin.
Rav Bunim told him, “The halacha is that if someone leaves behind a large amount of wheat (the size of an ‘omer ben sasayim’), it is not considered ‘shikchah’ (forgotten wheat that must be left for the poor) because one never really forgets about such a valuable amount and we assume that the owner of the field remembered about it very quickly. So too, if you had a momentary lapse of thinking about Hashem, it is not considered forgetting because it is certain that you remembered right away. Therefore, you have no reason to worry.”
The Chozeh’s face lit up and he thanked Rav Bunim for comforting him.
