How could someone take an oath and be "unaware of it"? (Leviticus 5:4)

 4 or if anyone thoughtlessly takes an oath to do anything, whether good or evil (in any matter one might carelessly swear about) even though they are unaware of it, but then they learn of it and realize their guilt— 

Leviticus 5:1 - 19

ESV - ¹ If anyone sins in that he hears a public adjuration to testify, and though he is a witness, whether he has seen or come to know the matter, yet does not speak, he shall bear his iniquity. ² Or if anyone touches an unclean thing, whether a carcass of an unclean wild animal or a carcass of unclean livestock or a carcass of unclean swarming things, and it is hidden from him and he has become unclean, and he realizes his guilt.

Clarify • Share • Report • Asked January 06 2023 • Jack Gutknecht